GFIs wouldn't add much to the cost if you're already having the electrician come out. Would it? I'd bet most of the cost is going to be labour either way. GFI receptacles aren't alot of money.
A high quality UPS will output very clean power. The problem is a high quality one won't be cheap. I think the better ones only use the wall power to charge the onboard battery that then feeds the UPS outlet. I did a google search and a small one outputting a true sinewave is close to $300.