upgrades for your amp/preamp

looking for a resource that helps you modify/upgrade your components. ie power supply, caps, pots and wiring.Thanks for your help! Orlando
Orlando, you need clarify your question.

Obviously you are interested in upgrading or updating your amp and preamp, but are you wanting to do it yourself and need a source for parts or advice, or do you want to find someone with the necessary skills do the upgrades for you?
Forrestc, thanks for your response. I am interested in advice and wanting to read diy literature. Who makes the best parts and where can I buy them. Thanks again
Here is a list that may help you out a little.