We have such a system. All of the material except for the automatic timer was purchased in or around Udon by our contractor. It required a new (about 6k Baht) pump to cover about 160 square meters at a time.
The difficult parts were finding two each 24V solenoid valves, and getting good enough coverage (during the dry season, some parts of the lawn get pretty brown without some use of old fashioned hose-end sprinklers, so we plan to "re-plumb" the system to incorporate thee valves, and add some more heads. At least I know that even when I am out of town for an extended period, I don't have to worry about the lawn drying up and blowing away.
The controller came from the U.S. - It cost only about 500 Baht in the U.S., compared to several thousand Baht for the only ones I could find in Udon.
Most of the watering heads are of the pop-up variety, but the housekeeper manages to break them every now and then anyway. With experimentation, I have found that the really cheap plastic sprinkler heads that have a spinning vane made of very thin chrome colored sheet metal give the best coverage -they do not pop up.
If your system requires more than two or three sprinkler heads, I strongly suggest that you have the thing built on top of the lawn and tested, then modified if necessary, then have it installed under the lawn. Revisions are much easier when its all on the surface.
The best thing you can do is read up on the state of the art. This (URL below) is the best tutorial I have ever seen on the topic. With it, you should stand a good chance of getting a good system put together, provided that the contractor listens to you
http://www.irrigationtutorials.com/sprinkler00.htmIf you would like, PM me and you can come over and I'll show you my system, including pointing out what I wish we had done differently.