for a 710, you can put any SG-SHAFT Engine in there along with a one pipe pipe, heres a picture
http://www.rdlogics.com/1pc.htm
I would get a either Novarossi, RB, Mugen.... all that are in the big names, pipe is the same but you can add RD Logics in there too.
Fuel, most people go with 20% or 30% oDonnell