If you have the typical "star" crack caused by a rock, meaning a circle or star shaped scar around a tiny hole or chip, it can be repaired rather than replaed. Typical cost about $60 and often it is difficult to see where it was repaired unless it is directly in the driver's line-of-sight. Many insurers will pay for this repair without any deductible, since it saves them the cost of a very expensive windshield. These repair services are often mobile, which is very convenient. I've had two such chips repaired, one on the motorhome and one on the car. The car repair is just about undetectable no matter how hard you look. The Rv repair is good but noticeable if you look for it. Neither are in direct line of sight and I never notice them when driving.
Any windshield shop could do a replacement, but there are outfits that specialize in large windshields and some will come to you rather than having to go to a shop. Often your insurer will make all the arrangements - they did the one time I had an Rv windshield half replaced. If your insurance won't cover the cost, ask an Rv dealer where they get their glass work done. Usually there are 1-2 shops in an area that are experienced in this sort of thing.
Any nationwide Safelite auto glass shop can handle this sort of repair, but they aren't my first choice. The local Safelite franchise may be well trained and highly professional - or then again, they may not.
There is an outfit called Duncan Glass that specializies in supplying RV windshields. They claim they can arrange for installation anywhere in the country. I've never done business with them and I suspect the workmanshipo varies depending n who the local contractor may be.
Duncan Rv Windshields
It seems to me that there has been some advice on this very subject. I have a 2001 Sea Breeze with a large curved two piece windshield. Can a regular auto glass guy do this? 
