1. A full on Bagwell Bowie.You guys would probably have fun making that, and it would be very practical for a lot of people. Minimal weight, maximum stabby, ideal for hiking (I'd take it in CG [Edit: I meant Battle Grade] of course).
2. Magnum Regulator (still .330" thick).A 12" bowie that weighs enough to split a mountain when you drop it, and you can split trees with the "air ride" suspension of knife handles. I love the feel of the Regulator handle, it needs to go on a bigger blade.
3. A nice big bearded camp axe. I've always wanted to try an axe for utility tasks.
4. It's a long shot, but if a CG Viking Broadsword could hit the streets under $500 then I'd probably have to get one (20-24" blade, 29" total, same as AK but a short handle).
Practically speaking, the Regulator handle would probably be perfect for this too.
As an aside, it would be awesome to see SR77 come back, it works really well in my SOD and Scrapizashi because it rusts so little. I know it's not popular and it doesn't hold an edge as well, but for a broadsword specifically it would probably be great.
Somehow I feel like a lightning fast Bowie should still be SR-101 though, maybe it just feels more period correct. The rest I'd love to see in SR77 but it's not a deal breaker.