Los,
Another option you have is if you dont need the unit that has the DVD player built into each headrest, and you just have the monitors, don't waste your money on buying a complete system or paying an upholstery shop to do it. They are super easy to do yourself. I have made countless sets and can say that even the novice can do them in an Escalade the headrest is super easy to work with and mount to. I will gladly give you a step by step if need be, but the first step is to go to ebay and grab a set of headrests, if you keep your eyes out you can find them for 30.00 to 75.00. then buy a set of monitors, I have a set of farenheit's in the caddy that I think where right under 200.00, you can have a complete set for the cost of the screens and the headrest no additional cost, if you want a little better monitor I bought a set of Alpines that I put in the wife's car that I picked up for right around 400.00 there is a night and day difference for me but the kids cant really tell or care as far as I know and the farenheit's are a good monitor. If you want headphones make sure that you buy a set with IR my farenheits are not the alpines are or with a headphone jack that you can plug a set in hardwired. There are IR complete kits available with monitors and headphones for a couple hundred bucks. Let me know if you need any help if you go this route I can try to get you some picks but if you simply need the monitors they truly are super easy.