You need to think long and hard before you buy one... ... ... ... . will you be doing ANY further mods to your truck?
Reason, there are several different kinds and sizes available:
elbow mount, 4" remote, and I hear there are 5" remote.
I started with a turbo mount Pacbrake which was great, modified to an HX40. by by pacbrake, hello BD remote 4". works well also. Quieter than the Pacbrake also.
HTH
George