Boy, have you opened a can of worms. I am going to see if anyone else posts, before I jump in here.
Now I will jump in. You have said you need a 30 KW. I tend to agree. You could also get a 15 KW and 30 KW. Run the 15 KW during the lower load times, the 30 KW in the higher load times. But that would make an auto start, auto transfer system even more complicated. And adds cost of a second gen set. The plus to the MEP-004A and MEP-005A would be compatibility.
So, you need to get smart on the MEP-805A, MEP-005A, if you want simple. I am a simple guy, and have more experience then most with these sets. I would take the MEP-005A. Hands down. Why? Simple. Its simple. The MEP-805A is several steps up the ladder in complexity, but of all the bigger TQG's, the most simple.
Both types have killer engines. Both have killer main gens. Its the sub systems that are the weak point. The MEP-005A has loads of info on line, and not just in this forum. TM's are coded A so no problem there. The MEP-805A is a little different. There is not quite as much info or knowledge available on line. The -24P, (the new version) is coded C, so not authorized for use by the unwashed masses. Not that I see this as a show stopper.
Parts are available for both sets. I think that even though the MEP-005A is older, there is less of a hassle getting parts. And prices may be lower. There are several people who have developed "new" parts to get around shortages. Things like static exciters can be fixed by normal folks with a bit of knowledge. The circuit cards are simple and easy to fix. But at the end of the day, the MEP-005A is older then most people in the forum.
AND, most attractive for you, would be the possibility of converting the MEP-005A to single phase. Something you can not do easy, on the MEP-805A. I will make no comment on auto start/transfer, as I would not want it. Its just another way to make simple, less simple. I never had it in the Army, and am used to getting up in the middle of the night to do a switch over operation.
So, I just want to add, yes I am biased. The MEP-005A is what I grew up with. But the MEP-805A is a good, strong running and dependable gen set. So if I were in your shoes, I would be reading up, getting smart on both sets. Look at some more threads. See what the problems are. Look at E-bay. See what kind of parts availability there is. Prices. Think about a parts set. Or a stand by to the stand by, if you will.
THEN start talking about your auto start/transfer stuff with the guys in this thread.
And if you want to talk about a trailer, then lets. I for instence would not get an M200A1. Thats what most of them are on. But thats farther down the line right now.