Good on you for riding it so much. You ask about an "overhaul" but please explain further what you mean. Are you having problems with it? If so, what kind? Do you want to make it look different (e.g. paint and chrome)? Do you want to make it ride better and more comfortably? Are you just looking for a list of common preventative maintenance? Something else? We can definitely help you with any or all of these but we need to know what you are asking for.
From a preventative maintenance point of view, I would recommend also changing the other fluids which you do not mentions. These are the brake fluid in both systems, replacing the coolant, and replacing the fork oil. All of these can be done by yourself rather easily although to get the caps on an off the forks to replace the fluid it is very useful to have two friends to help.
Get a copy of the service manual which is available here on the Cafe for free.
As for "upgrades", the first and most important one for most people is a new seat. The stock seat is horribly uncomfortable to most people. This is NOT a cheap addition. After the seat, your "upgrades" depend on your personal preferences and your budget. The sky is the limit
