My April '88 copy of SB 11-131 ("Vehicular sets and authorized installations") covers the M925 - but doesn't specifically list the A2 model. Radios listed are AN/VRC-46, -64 and AN/GRC-160. The PLRS Surface Vehicle Unit is also authorized. Installation kits that would list specific antenna models are: MK-2301/G; MK-2538/VSQ-1 and MK-2562/VRC. A later Supply Bulletin specifically listing the A2 might add other radios. Hope this helps!
Cargo trucks dont get the EPLRS system. I know they are authorized to, but I never saw one that did. Plus, you'll never find one out in civy life, and even if you did, you dont have the litterally multimillions of dollars of other commo stuff and vehicles that are needed to make the EPLRS system work. I dealt with FBCB2 and EPLRS and all that stuff in the Army.
Realistically, your options are the VRC-12 series of radios, and if you can find one, a NON ICOM SINCGARS. Cdub put a system in his M925A2...