i had 2 w3s the same as yours, they were the dual 2-ohm version and had them running off a jl e1800d, cracking amp, perfect for 2 of these subs, they sounded immense, youll deffo need sound deadening though lol
yer the carpet is easy really just cut to size and use spray glue or super glue, you can get self adhesive carpet which i bought aswell but didnt stick very good
hope that helps and that looks like a decent box too me