First, Welcome to the "nut house"
Second, modifying the stock 'dual' seat to a single seat may be a problem as the seat latches are under the passenger seating location.
Corbin (corbin.com) blows a new seat pan out of fiberglass for new seat orders, they have a template/mould for the C-10 seat pan.
I'm reasonably good with fiberglass, I built a four place 220mph aero-plane out of glass from scratch, so I could *theoretically* build you a single person seat pan. But the latching mechanism would be an issue, and it would require mods to your frame than I can not do (or suggest).
I don't think the stock/OEM seat pan is a candidate for modifications (it's lame ass plastic), but a fiberglass/metal seat pan could be. See "corbin" above.
And, welcome to the "Nut House", if I forgot
Rick