Electric Flap Changorver
Scott,
I just did this converson on my 6A.... As far as the cost goes, I bought the whole nine yards from Van's including the pre-welded and powdercoated Flap Actuator Weldment and the very cool Flap Positioning System. (Total $725 + shipping)
The actual installation work was not the easiest project I've ever encountered! Of course working space in your plane is always a limiting factor and working in a hot (100?+) hangar didn't help either. One thing you'll find you probably have to do is replace the flap actuating rods as the ones on my manual system were way too short. I've opted for ones made out of 3/8" hex aluminum as they are way easier to tap than trying to hold Van's smooth round tubing in a vice not to mention they are much stronger!
As with all retro-fitting jobs, running wiring and just squeezing parts in and out of very close quarters lends to cut fingers not to mention sore knees and an aching back... the end result is worth it though.
Good Luck!