stock flex tune is great
Fioroni is great but some screws are in diffent places so you would need to mod your conversion alittle
http://www.amainhobbies.com/product_...Coated-Chassis
Matrix carbon chassis is good too (its what i am useing) it has built in replaceable skids
http://www.matrixconceptsinc.com/pro...p?idCategory=2
there are afew more out there, but these are the 3 i have used