Both brands are pretty interchangeable.... I have owned both, and abused the daylights out of both brands, and they just keep cutting.... Both brands have three distinct lines.... a low-priced Homeowner line, a mid-range medium duty line (Rancher for Husky and Farm Boss for Stihl), and a high priced Professional line.... for your stated use, the mid range would seem to be the ticket. The saws in both companies in the middle range come with variations of the Half chisel tooth design, which is in line with your task There are also electric saws from both brands. Those have some variations in capabilities, and are mostly lighter duty saws that I don't think I'd use for more than light duty limbing... some guys who do the aerial stuff with trees like the electric saws because they're not running until you pull the trigger.... you're never balancing on a shaky limb trying to start your saw. And speaking of light duty saws.... I'm not a fan of any of the minor brands of saws.... Echo's, Homelights, Toros, Craftsman.... Buying a quality saw the first time around is always a good idea...
Think about a spare chain and bar for each saw you're running.... and a sharpening kit.... I have a vise and holder that slides into the trailer hitch on my truck to expedite sharpening.... Crepe Myrtles are hardwood trees, but they're actually softer than some pinewood...... Make sure you ask for Half Chisel chains for your -spares... they're a more forgiving and easily managed chain.... I stick with the same brand replacement chain as the saw.... Though a lot of guys out in the woods do use the Oregon brand bars and replacement chains.... I stick with Husky for Husky and Stihl for Stihl.... Same with fuel.... These days when you buy your saw, you can get a guarantee/warrantee/ protection plan.... that plan is extended if you also buy the branded pre mixed gas.... it doesn't hurt, you don't have to do anything but shake the can up a little to use the stuff, and if you manage to bungle your saw, having that slip that says you were using the same brand of gas mix as the saw.... makes customer service a bit less of a hassle....
Buy two or three times as many wedges as you think you may need.... and have a midsized one hand sledge hammer handy.... if your blade gets stuck, it's usually pretty easy to bang in a wedgie or two and free the blade up.... A bar wrench usually doubles as a spark plug wrench, and having one handy along with a couple spare spark plugs is always easier than running all the way back out of the woods and down to the nearest NAPA to see if you can remember what plug fits your saw.... If your blade is really really stuck, and the wedgies don't help get the saw out, you can use the bar wrench to remove the bar and toss another bar onto your main saw so you can cut your saw blade out.... If your saw gets stuck in a really dicey situation, some times its nice to be able separate your expensive saw from a more replaceable bar and put the saw in a safe zone where it won't get mangled when everything turns southwards...
Did I mention your BUS.... (It's like a BUG only is not a gun its a saw....!) Back up saws are a thing.... depending on how many trees you're dropping, a few extra saws floating around can be a huge driver for continuous operations.... NOT so you can be dropping two trees at once (HUGE safety issue.... work one tree at a time... if it gets hung up on another tree, it is never a good idea to cut the standing tree and drop two trees... ) , but more so you can maintain momentum and not have to muss and fuss too much to free a stuck saw or a fouled plug.... Other momentum savers are various log handling tools.... I'm an old guy, I like Pickeroons, a good log jack... they just make handling trees and chunks of trees easier, and have saved my back much wear and tear.... Chain saw chaps are a real good idea.... realize that chaps that will protect you from a gas saw may not protect you so well from an electric saw.... a good hard hat, a good face shield (I like screens better... they don't fog...) Ear pro and good gloves, too...
We don't have a lot of those trees up north.... not sure how old they are, or if they've grown much past the ornamental stages.... but unless they've grown old and unruly, they should be pretty easily handled. As far as the stumps, Hardwood trees have a lower absorption rate than pines and variations... so killing roots and shoots takes a little longer, and usually calls for stronger herbicides. Around here that means glyphosates.... mostly you've gotta have a license to use them, and you need to be very careful about ground water and your well when using glyphosate and derivitives... The herbicides you can get at the Depot or Tractor Supply are usually polyphinal derivatives.... Copper nails.... you'll need a whole whole whole bunch of them, and they're significantly slower than either of the above methods.... Pulling the stumps out is probably better than grinding them down, as far as preventing new shoots from springing forth... always pull a stump straight up rather than to one side or the other...
Wish you well!!!!
In my experience, most people get way more of a saw than they need. My main use saws right now is an older Stihl 026 with an 18in bar for felling, and a Stihl 021 for limbing and most bucking. I have bigger saws that I rotate usage, but cutting with these two is never felt like I need more power. 
