I used seats from a 2003 Mercedes CLK 430. The key is to get seats from a 2 door, so they fold forward. I had to fab one mount on the inboard forward side of each seat, then welded fat spacers on the rear mounts to get it where it needs to be. Plus drilled a couple holes. All in all, not to difficult.
With regards to dash/instrument cluster, check out
www.intellitronix.com. Similar deal to dakota digital, but much less expensive. Keep an eye on eBay...I bought my 6 gauges cluster for 180ish delivered. I seriously disliked the 72 cluster I had and wanted something different and clean.
FYI if you do something with a center console. The hump is NOT centered on the car. Ask me how I figured that out....LOL