Hi Daniel!
I'm fortunate enough to have both a Stormtrooper and Boba Fett costume, and I just recently was approved for my Boba, so some of the details are fresh on my head. So, here's a mini dump on my experience so far. (I just the 501st in January of this year)
Stormtrooper - I went the route you're thinking and had someone build my TK for me. I used RS Propmasters, and I was super pleased with the kit. It did have some adjusts that needed to be made, and for the 501st, it's not only about being accurate but it does need to fit correctly. Measurements being sent to someone can only do so much! Anovos is the official licensed Stormtrooper that a lot of folks have on order, but we're still waiting to see how those turn out, and how much in the way of modifications are needed to make it good to go. My daughter was born right before I ordered my armor, and I had them build it as I figured I wouldn't have time to get it done in the next year or so. Knowing what I know now, there's something cool about putting it all together yourself and I'd go that route given the choice again. There's lots of guides out there, and we do hold the occasional "armor party" where everyone can get together and work on their armor. I imagine once the Anovos kits come in, there will be more than one! Either way, if you haven't already, check out
www.whitearmor.net/forum/ for all things Stormtrooper. Sounds like you've got a good start on info!
Boba Fett - I want to say we have 4 ROTJ/SE Fetts active right now? No ESB that I'm aware of, but pick the suit you want! It's a huge time/money investment for Fett, so if you go for him go with what you want to build! For resources on how to build a Fett, go to
www.thedentedhelmet.com and prepare to research! I started my Fett in end of February and was approved early this month, and that's considered a pretty fast build I think.
Feel free to ask questions, and we could always use spotters at events if you want to check out the armor up close and meet some new Star Wars fans!