I used some out of a 2001 Civic that I found on Craigslist for $50. These are easy to find since the import community likes to change them out for racing seats. They worked out great... the front mounting bolts bolted right up without modification. The drivers side right rear (closest to the door) I flattened out and hogged it out about 1/8 inch and used a few washers to make it level with the front. For the Drivers side left rear, I drilled a hold and bolted it down, no washers needed. Passenger left rear (closest to door) I used a piece of flat stock I had laying around and bolted it to the floor in the original hole then bolted the seat to the stock. Passenger right rear I drilled a hole and bolted it down.
Sounds like more work than it was. From start to finish was about 30 minutes including removing old seats. The civic seats are very comfy, are 6 way adjustable, and the driving position is raised about an inch which makes it a lot easier to navigate the trail.