discovery 3 rear middle seats

[twinpipes]

I am going to test a 2009 disco 3 tomorrow to buy with 78,000 miles commercial. What should i look out for before buying. I also have tried everywhere for rear middle seats with belts and fixings in cloth preferably but not essential., was quoted £1500 which is steep, where could i locate a set a bit cheaper. I'm in Northern Ireland so would have to ship.
Seen these seats by, but has anyone fitted them and are they compliant to insurance or should i keeping looking for originals.
http://www.scotseats.co.uk/landrover.htm
http://www.scotseats.co.uk/downloads/DiscoveryFreelander2commercial.pdf