I've seen aluminum ATV/UTV ramps for sale. 1000# capacity. They look like they'd work pretty well with my M105.
I own a set of these ramps for loading ATVs...
1000 pounds is deceptive. It's based on assumptions about wheel base and weight distribution. It could be accurate, but I think it's optimistic. I see ones out there with much less metal than mine, with the same rating. I believe the safety factor to be about zero.
Add to that, mine are ten foot ramps. They also come in twelve foot a couple of places. Same metal used, just cut longer. While the load angle is less, I'd bet the flex would increase signifigantly.
No regret's for having spent an insane amount of money for these ramps, as they are not something that I could fabricate (at least not if I hope to still put them on the truck by myself) but they are what they are, and they work, but they aren't spectacular.
Anyway, the original question...
Weight rating aside (for me anyhow, as you said you'd be making these yourself I hope you won't put that aside...) At ten feet long, I can load an ATV with
acceptable confidence, but it's a long way up from level ground. If the terrain works against me even just a little bit, driving is out of the question. (They go up/down with the ATV's winch). It's much more reassuring when I can get the terrain to work in my favor, even a little depression to get the wheels into makes a BIG difference
Suggestion- Go as long you possibly can. Even twelve feet long makes for a good steep climb up into the truck. They're about twice as steep on the way down as on the way up. Since twelve feet is just what fits in the bed, twelve feet is what I'd recommend to you. I'll also say that when it comes to storing the ramps, there are many times when I've had other things in the bed (of several trucks, not limited to the deuce) and it was inconvenient to have the ramps exactly straight front to back. Depending on the width, two to three inches shorter than the bed with th gate closed is ideal, then you aren't commited to exactly how they must fit in there.
Also, do not neglect to terminate the top of the ramps with some type of "locking" feature. Something to "hook" is great, but at least a "lip" like commercial ramps have, so that you can ratchet strap them tight against the truck. The longer, steeper, and higher the ramps are, the worse the consequences of a "shift", and the greater the likelyhood of a "shift"... However you accomplish it, they need to be HELD in place, and not assumed that gravity will keep them there once you drive onto them, because it will not.