Look around for info., on Impulse exhaust systems, and impulse turbo installations. Interesting stuff.
Stockers should be fine.
You'll probably need to do you own chips to get this right. So you might as well start reading up and getting serious about tuning. I don't mean to infer you don't know, but to unlease a twin setup, means really knowing what your doing to get it right.
I'd also suggest you look up the info on using a Translator Plus, and then going to a blow thru MAF. That way you have all the computing power you could possibly need on your side.
Twins are cool.
Done well, should be fantastic.