... We also expect them to be heavily customized and sold by many makers. ...
I could get in on that, so long as the price is low enough to make it profitable. Been doing it with those other bali kits for a while now. It's cost me more than I've made, but just so long as I come close to breaking even, I'll keep doing it. I would love to try something different.
Overall length should be between 9 and 10 inches. For me, that is a must.
As for blade steel, I'd want something easy to work with, inexpensive, with decent edge retention. Do we really need stainless?
As for handles, I'm thinking stainless liners, and let the customer choose from a variety of scale materials (or supply their own). Doing so would allow for:
1 Lesser weight.
2 Immediate customization.
3 The ability for a newbie to put together a good flipper without an array of power tools.
4 A variable price point.
Plus, while I've gotten pretty good at building hole templates, and I can drill through thick stainless all day long... Some days I'd prefer not to.
What do you like better sandwich or solid handles? Why? My thoughts are the solid is more "solid" and more customizable but is the little extra weight a major issue?
Perhaps, but it depends what you're customizing. Modifying things such as the washers or spacer material (for flipping dynamics) is a lot easier to do in a sandwich than a channel.
I put ball bearings into the other kits I put together. I can't do that in a channel.