Top End rebuild

What is a good kit to buy for rebuilding the top end. Not sure if I need a piston, or not but rings for sure and valve seals.

Reason for rebuild is my base gasket is leaking oil, and it is smoking blue smoke, so I thought it would be a good time to rebuild..

Trying to keep cost down some also, thought about a 686 kit, but I think I will just go back with stock.

Thanks