Welcome!
I have 10 GIK 2ft x 4ft 244 panels in my dedicated, well insulated 8ft x 13ft x 21ft room. Six are "full range" and four are "bass range". The four "bass rangers" straddle the front corners. The six are at first reflection points on front, side, and back walls. Frankly, in an ideal room with three subwoofers they make little difference no matter how I positioned them, but the "full rangers" have been tremendous improvement in less than ideal rooms.
Suggest reading Floyd Toole's "Sound Reproduction" 3rd edition as the consummate audiophile primer into understanding how speakers/subwoofers behave in-room. Hopefully the room you have in mind isn't small or squarish and is well insulated and dedicated to the cause. After that if you follow Toole you'll look for speakers that measure well via Spinorama or Kippel. Toole would recommend shopping speakers before treatments. Next check out audiokinesis.com for introduction to subwoofer swarms to help with inherent in-room bass peaks/dips. After that pick out amps that serve the speakers and go from there.
