[camp guy]

I can second the use of Gilford Well.

One point to keep in mind is that an irrigation system needs routine maintenance, including end of season shut-down and beginning of season start-up, so you want to discuss this with the installer and find out if they do the maintenance, or if they just install.

Another point to think about is mapping your yard and indicating the location of each sprinkler head, and if it is zoned you need to show which heads are in which zone.

One last point, if you are on municipal water be prepared for an increase in your water bill. If you are on municipal water and sewer you may be able to get a waiver of the sewer fee relevant to amount of water you use for irrigation.