OK, those are all essentially soft/easy-cutting woods. That reduces power demands substantially.
You looking to just drop these size trees, or cut them up every 16" for firewood? The answer to that would influence my recommendations. If you're blocking up big diameter trees, cut after cut after cut, I'd probably just jump straight to MS500 or MS661 territory and skip the smaller stuff.
Ultimately, back when I cut way more trees than I do nowadays, I found that there wasn't much I couldn't cut with a 28" bar hanging off a warmed-over 066 Stihl or a 7900 Dolmar. Full comp chain on both, and an 8t rim on the 066. Never lacked for power set up that way. But you could definitely tell the difference between those two saws in full buried cuts.
For your purposes, a Husqvarna 572/18"+28" sounds about perfect. Buy the two bars and honestly, you won't be using your current saw much.