Slightly off topic (since you asked about bi-fold vs. hydraulic lift) but...
I went with an accordion-style door from FoldTite for my new hangar. The price was about half of what I would have paid for a bi-fold, and about a third of the bids I got for hydraulic. It was easy to install, takes about a minute to open, and works even when the power is out (it's 100% manual). It's also dirt simple, so if anything was to go wrong I can fix it myself with parts from the hardware store.
The only down side is that you lose a bit of clearance on either side, which may or may not be an issue depending on what all you're going to put in there. The opening on my building is 40' wide but the maximum clearance with the doors open is a bit over 37'. Not really a problem for an RV-6A.