Ryan, it is a 7.5' x 12' bed. No dumper yet :crying: shooting for one next season. Alot of the pictures of my truck you have seen were a 8' wide bed but 12' long. If you've seen it with the tall red steel sides then that is a 7.5' wide 12' long bed. I changed the beds to accomodate the sides, and the few inches in width dropped helps visibility issues with the mirrors and trailer and all.
If you go with a dumping bed on your blue truck, I think 7 or 7.5' wide would be good, and 8 or 9' long I'd say would be a good managable size. Thing about that type of setup vs. what you now have, you will gain capacity in weight and volume because your current setup has to weigh quite a bit by itself, and takes alot of usable space too. Flatbeds are more versatile as you know, with easily interchangable side options, the ability to side-load pallets (run a spreader on the receiver hitch and load pallets of salt on the bed in winter), not worry about it getting beat up a little here and there, unlike a pickup bed worrying about getting it dented.
Good luck with everything. You have a nice setup. How's the trailer situation coming along?
7.5' SnoWay w/Pro-Wings call 812-371-6069