I would go with the Xray, Mugen and maybe the 8ight... The mp9 is waaay over priced in my opinion...
But also look what you're LHS stocks... But I see u live in Australia, so maybe you shop online? Then that isn't an issue.
And see what the other guys run, sometimes you can share parts (when they're kind, lol) and set-ups.
But if you have something that not many people have.. Then you pick that one...
I'd say, look on internet for reviews etc. and choose the one that feels the best...
Maybe u can try cars at the track... Good luck