Your on the right track with your mods now that you got more air coming into your engine you might want a better intake, I have Trick Flow street heat upper and lower intake which flows, as for heads theres a wide market out there right now I think AFR 185's and Edelbrock heads are whats hot along with some MAC or BBK long tubes or shorty headers to get all that air out. I think the 1.6 would be fine with mild heads and a stock or mild cam. Hope I could help
I have a set of gt40ps on
www.ebay.com along with some headers
Item #'s 2461498353 and 2461505285