RE: sprint 2 or TT-01 or TC4
Yeah go the TT-01 to start off cheap. You can upgrade them so much that there isnt much left of the original chasis hehe.
Check out RCMart.com for hop ups, thats where I order most of mine from. Also check out [link=http://www.etamiya.com/shop/index.php?cPath=302_331&osCsid=5aa9c35c057145ad7fe 0b270b27779a6]eTamiya[/link] for lots of alloy parts.