Well, as far as SWCG goes, you can go either way. Personally, I'm happy with my Autopilot.
First off, while an SWCG can make life easier, it won't make it A LOT easier if you're always and home and good at maintenance. Because if you are, you'll spend 2-5 minutes a day testing and adjusting your water and 15-45minutes once a week, unless you hand-vacuum. If you travel a great deal and have to leave the pool unattended for days or even a week at a time, an SWCG can be a big help.

It will NOT save you money. It will cost more in initial cost to run than buying bleach and Liquid Chlorine. Plus figure every 5 years you'll need a new cell...at aprox $500/pop. That's at least 5 years worth of bleach/chlorine on a 16000 gallon pool.

Still, this builder sounds like he knows his business, recommended the surge protector, and recommended you get it separately. So I'm guessing he'll know how to install the SWCG, which includes the necessary wiring. I did my own and merely piggy-backed it off the pump's timer (220v) and plumbed it in. But I'm an do-it-yourself addict. If you DO have him install it, be sure to have him put quick-release cutoff valves on either side of the cell. Most SWCG cells have their own filter screen that needs to be cleaned from time to time and it's MUCH easier to do it if you just shut off the pump, flip both ball valves, and open it up and clean it. Also, if you have to service or replace it, it's easy enough.

We do have a couple of SWCG experts here, PoolSean comes to mind, but I haven't seen him posting in a while.