Photo Essay of C-1 Outfitting
Using webbing, Rings, and a foam bulkhead for outfitting

For plastic boats using "O" or "D" rings can be a great way to outfit your boat.

Materials:

-2" webbing from EMS
-4 rings (I used circular ones as I couldn't find heavy-duty "D" rings) from Lowes (like a Home Depot, etc.)
-4 stainless bolts (1/4 by 1" I think), 8 big stainless washers, 4 nyloc nuts, 2 big rubber washers (slightly larger than the stainless ones.these go on the hull on the outside of the boat).

Specific to the Wheelboy:
Thigh straps-I removed the pedestal (8 bolts in front, 6 in back if I recall-you have to unbolt the aluminum strap from the boat as well as from the carbon-kevlar plate.note that you DO NOT have to undo the nuts all the way on the plate-it is slotted so it can slide in and out of the aluminum bars), and then drilled holes in the sides of the "bar" just in front of the seat to bolt D rings (Dagger Atom style-stainless steel hardware with nyloc nuts and washers through webbing doubled back over the D ring and sewn into itself). I removed the pedestal so I could attach the nuts inside the "bar". Other boats
Attach the webbing to whatever you're using to convert, be it an internal rail that is already there (Liquid Logic boats among others), Randy's Fence Rail conversion, TEAM Etc's conversion, or your own.

I attached the upper half of the strap to the "flat spot" near the rear of the cockpit rim that fits a washer (stainless steel over rubber) rather nicely. In general look for a spot on the top / side of the boat near your hips (not in front of, unless you plan on re-using a kayak seat attachment point (which is a great way to go as the boat has been built in mind with that being a bolt-on point stress-wise)).

I like two separate points for the strap attachment (if I ever blow one out (yes, it HAS happened.) I can just attach it to the other side and take it easy.but at least I can finish the trip (my "normal" trip is a 17 mile wilderness trip.so if you're just park and play it's a bit of a different story:) ).

I've also added a front bulkhead that keeps my knees from moving around too much. It's press-fit, so I can take it out to access the bow for a water bottle, let larger paddlers try the boat, etc....

A few images:

Seat view, no Bulkhead. Center Rings, Bulkhead in (yes, it's crooked)

Bulkhead shape (note notch for front pilar wall). Fit of Bulkhead

Back ring attachment (in flat spot in Wheelboy), Internal rear ring, another bulkhead shot. Bulkhead fit