I agree with babu, the cost of the seats will run you to over £4k.
You'll need to modify the rails, which will mean modifying the soundproofing layer and carpets, you may need to look at the side panels to ensure enough clearance, but I'm just throwing that out as a precautionary check.
The loom will partially work, but you'll definitely need to do work there, either by getting a 30 series partial loom, or creating one from scratch.
I think you would need to really love your 20 series to spend that amount of cash, I think it may be more cost effective to buy a 30 series.
You can buy new front end that gives you a 30 series look, bonnet, wings, bumper, grill and lights, and I've even seen the rear converted by chopping a section of the rear, and fitting a new quarter panel to for the new higher up lights and new tailgate, bumper.
Bonkers money, I'm not sure how the Malaysian owners afford it.