i would start with the dynojet kit, k&n airfilter and a hmf exhaust...you will see great results with those mods alone
Check out ATVOutfitters, I got the HMF Utility Pipe, K&N, and jets in one package- $300 plus shipping Oh yeah, it came with the Outerwears Pre-Filter too.i would get the k&n and jet kit off ebay, as for the pipe you may need to look elsewhere....there was a post on here somewhere where someone got one for about $212 including shipping but there is a k&n on ebay for about 40 bucks and a jet kit for about 50