HoS is great. I've bought shirts, ties, flashes, a towel, flags etc. off of them from a few different orders. It's always arrived in good time and they've always helped me - like when I phoned asking for info on sizes.
I'd recommend them... although check their ebay account first as you might get your stuff a bit cheaper:
http://myworld.ebay.co.uk/heritageofscotland-net