juliano's for belts:
http://www.julianos.com/seat_belts.html if you remotely a big guy you may not like the length of jcwhitney's belts shoulder harness
these are things you should consider b4 ......
BESIDES
the small floor area that you would use to hold the belts to the floor have several advavtages. the seat support rim above the floor helps to stiffen that area and you could also add a small plate below the floor, welded or not. the area where the shoulder harness bolts to is down in that deep pocket area that has many different angles for rigidity. :p
dave's site for installation:
http://www.speedprint.com/Deves50/seatbeltassembly.php
