Thanks, if you install hotcams as an example, do you need the stiffer springs or what are they for? What do the gastket and springs run for?

 

Stiffer springs will hold up better at high rpm's (keeps valves from floating). They are not needed but most people reccomend them.
DRZe valvesprings are ~$10 each (4 total) from a local dealer. Base gasket is ~$12. Stock compression is ~11.3:1 the base gasket bumps it up to ~12.3:1. You will need to run premium gas with the higher compression.