Have a ripper and I wouldn't use it for burying any thing larger than electrical wires (if that) as they don't leave a clean trench -- and aren't intended to either. Also, not likely to get the lines deep enough without a lot of additional work to prevent waterlines from bursting anywhere where the frost line gets to be more than a foot or so deep. While it might be capable of dealing with rocky soil, it wouldn't take all that large of a rock/boulder to stop a <5,000lb tractor and it's very unlikely to deal with any solid rock formations as rippers/sub-soilers/middle-busters are intended more for use in fields to break up hardpan.
Renting a trencher if at all available would likely be the more cost effective and labor efficient method.... and depending on the area they may/should already be set up for dealing with rock (wouldn't make much sense for the rental company to do otherwise in a rocky area). ...and depending on your local rental market you may very well be able to rent a trencher for not much more (or possibly even less) than that implement costs.
Might just be me, but anything 1" or over I'd actually lean more toward a mini-excavator or backhoe over a 3pt ripper (even where frost lines aren't an issue), and a trencher over any of them for any sized piping/wiring where the trencher could handle digging a wide enough trench. But, I also don't like having to use a shovel in the clay soil/loam I have on my property either (it's not a lot of fun when it takes >300lbs to drive a shovel fully into the ground).