I only have one problem now.... I know what parts to buy, but there are so many different brands and models, how do i know what to choose?

What piston head would you guys recommend,
And what cylinder would you guys recommend?
do i need a new cylinder head?
also does it matter what brand of spring i buy? i mean if theyre M90 then theyre all gonna be about the same power right?
Thanks alot again,

Avose

