Lots of people like Vega and Smith area. I have been to neither and drag my quad back to Ontario where its unlimited riding.
The quadzilla you must do the rm250 wrist pin upgrade and brass or steel crank inserts. Some guys reinforce the ears on the cylinder. O ring the head etc. Jerry Hall provides all this but he is pricey....but worth it. Iceracer (Carl) on the quadracer hq forum also does this work as well as DrQ, Duncan, Pete S (cant remember his shop name). Basically register on the quadracer forum and do some reading. Ultimately I sold my 500 due to parts availability and price. Banshees are everywhere.