Welcome to the site !!
To be honest OEM is the most reliable ... but unfortunately aftermarket is more cost friendly .... I know when I replace my piston in my 20 450R I am going OEM , simply for the fact that it has been trouble free , so why not replace it with the same thing , plus I know it will be a exact fit ...... my other choice on piston would be JE ... but undecided on crank , etc. .
As far as actual "Kits" go , the Wiseco Garage Buddy complete kit (Wiseco Part#:PWR143-100 ) is a good deal and pretty much gives you everything you need to rebuild , minus head and valve components ( I think you get Valve Guide Seals with it) they are about $600.00 -$700.00 U.S. depending on where you get them , as far as crank goes , I have seen and heard great and not so great things about both Wiseco and Hot Rods cranks ..... maybe go OEM on the crank and get the rest Wiseco ??

.... Hope that helps ...
