There are plenty of places to get airbags. It depends on where you live. The best thing is to go and talk to the shop that is going to do the work or give you the parts. They should be able to give you all the info you need. If not, go somewhere else.
There are also a heap of sites out there that give guides on installing airbags. Have a look at www.fbimini.com. They have some install guides on their site. You could probably buy a specific kit designed for your truck.