Yeah I was hoping to just find manual door panels from an 08+ for an easy swap since mine is all manual. Funny you should mention swapping electronics though.... while I was searching today I thought "hmm maybe I can add power windows and locks". Well, I spent about 3hrs at the jy today trying to pull the full loom of wires all the way to the fuse box from an 08, and then took them over to an 07 van to see how things marry up for plug-n-play. Long story short, they changed up the colors and the fuse boxes are totally different between 07-08 (or at least that was the case for the two vans I was experimenting on). I think it's definitely possible but it would be very involved and time consuming. Given that electronics aren't my strong suit, I eventually cut my loses and decided crank windows weren't so bad haha. I found a manual 08 door panel so now I jut need to wait for a drivers side panel.
If my van were already wired for power windows and locks, I would definitely go with the switch modification that you suggested. But running a whole new loom and transferring all of the guts from door to door looks like a PITA.