I admire you for taking the time, effort, and cost it needs to enter such an exclusive realm of craftmanship. I am certain you will produce some very nice knives. I can only contribute with an user's point of view, so I will dish out my two pence because I dream of a knife high-ended on my wishes, not on big company marketing, whatever :
Blade steel : reliable, easy and lasting = 1095 (way better steels are available but way more expensive : is it worth it ?, you choose...)
Slipjoint : put on the strongest spring ever (for strongest "no closing on your fingers" safety...), forget the nail wheenies they are tended at by the current market...
Long pull : of course, especially with the beefy spring... (and a nice handle cutout for "pinching", when I have greasy fingers or soft nails)
Half stop : of course (once more), safety, convenience while opening, closing...
Wooden scales : just my taste, I just can't get stoked on Micarta...
Stag scales : see above
Bone scales : see above
Horn scales : see above
Good luck and get well, I'll be back if I discover some more groundbreaking news...