Hi Ric,
I just purchased a complete interior set, mixing from the different vendors to gain the best 'deal' I could manage. I believe most get their stuff from AH Spares though. A number of the bags the material/parts come in have the AH sticker on them. Mike was right about the Moss coming from Stateside, but the only the BJ8 kits come from England if you read the fine print (I don't know why only the BJ8 ones do, perhaps the rear seat back is a special stamping?). So from what I've learned, and I may be incorrect totally, but it seems AH Spares seems to be the centralized bin for a lot of the parts for Healeys.
So, anyways, I ordered the trunk kit, and front seat pans from VB. The carpet kit, dash, and door pads from Moss, and the interior kit in red leather from UK Healey. The quality seems okay, not what Heritage would provide I'm sure, but Steve has been doing healey restoration for years and this is what he uses. The Moss video is essential to you or your upholsterer installing it though, I highly recommend you get a copy. There are tricks to the whole thing, not visible on disassembly. I am currently doing the rear seat back and bottoms, and am having to sew on some beading and vinyl strips that were missing. Not a big deal if you are a professional upholsterer, but for me it is a problem. I'm currently emailing back and forth to Steve at UK Healey Center on what/how to proceed and he is very helpful. He just sells the kits though, a different firm apparently makes them.
I picked front and rear in leather which apparently is why I'm having some trouble. The rear leather kit has vertical flutes (like tuck and roll I guess) rather than the embossed squares in the vinyl kit. This makes the whole assmebly behave differently, and the fluted section doesn't just fold under the seat back, but I have to trim the foam away, and staple it under and add some piping where it staples to the wood. With the vinyl kit, you just staple it to the wood on the seat back, piping is already installed. Which appears to be much easier.
My next step is the front seats, and since the car is still in the paint shop, I have to wait on doing the trunk and carpets.
Oh, and if you are shipping it from the UK, have it shipped directly to your door. It may look cheaper to pick it up at the airport but after you factor in the customs agent fees, the gas, the misc. fees etc. It would have been cheaper to have UPS deliver it to me. Have them make several small boxes if possible so UPS can take the whole shipment. I tried to do the airport pickup way, but it ended up costing about $200 more.....plus 6 hours of driving time and coordinating with the customs agent, giving them power of attorney for the package, etc.
Let me know if I can help any further.