What about EddieO of Br00d? or dare I say it .....Big Jim...who's forum I just gave you.....
Yes these are very open ended, and hard to answer without empowering yourself with some knowledge. Start off with what the "hot" track motor is at the track you are going to....then worry about the "best" motor when you get some good tunning knowledge under you.
I also hate when everyone starts spitting up gear ratios/roll outs etc. ....each motor is going to be different, even with similar motors you can get a huge varience of what gearing to use. Just use your track times as a guide, move up and down from there, agian use your own knowledge/input as your situation will always be different.....
These posts are almost as bad as "which is the best touring car?"
bottom line is any choice you've given will be competitive, you just have to find "your winning combo"....
Oh and hello Stormy