Get the brightest thing that you can. You need to fill something that is over 60 feet wide. At minimum, you are talking about needing 30k lumens and probably 3-phase power. You probably want a brighter image than that.
You could also use multiple projectors and either tile the image or stack the projectors (overlap multiple projectors). Whether this is a good idea or not depends largely on how much time you have, how much you care about resolution, and your budget. Companies like AV Stumpfl have software and hardware available to make seamless multi-projector shows possible.
The throw distance depends on the lens that you use. Lenses are marked by "throw ratio," which is the ratio of the width of the image to the throw distance. A lens with a 2:1 throw ratio will produce a 10-foot wide image at a 20-foot throw. A lens with a 4:1 throw ratio will produce a 5-foot wide image at the same throw distance. And so on. Most video projector lenses are zooms, and will have a range, like 4-6:1. I would suggest figuring out where you want to put the projector(s) and then renting the appropriate lenses for them.