Glad to hear your enthusiasm. I'd be happy to do it if I lived in the area; but hopefully you'll find a taker there in town.
I would guess your total work time would be 4-8 hours.
This time quote is unrealistic however, you really need to consider the time it takes to buy the parts and then set up the SOFTWARE, which is quite different for each and every set of GPUs your run.
You haven't even stated your desired OS, either. It doesn't sound like you'd be comfortable using command-line or unix interfaces, so you'd need a license for windows and then use Bitminter as your pool/software for ease of use.
Then, of course, who will support your rig(s) if you have a problem in the future?
Lots to consider here... But don't let that stop you... Just accept that there is lots more to learn and get to it.
Good luck!