As far as I know they released it on both VHS (I know outdated) and recently DVD, the problem is I am not sure if it has been released for US consumption yet or if it will... Try Amazon but the only version that I saw was region 2 encoded... I did find it on the UK version of amazon but that might bring about region issues as well. Hopefully the BBC will realize that there are Dr Who fans on this side of the pond and give us the entire collection. Also if you like the 8th Dr check out the audio programs that he did...that is if you haven't already!
Hope this helps
Also, it's dead easy to play Region 2 discs. You can get a Philips player for $40 and hack it easily to play any region. This is not at all illegal, by the way. I buy all sorts of stuff off British Amazon. Amazingly, it's often a lot cheaper than buying DVDs in the US, even with the shipping, and you can find many films and TV shows that aren't economical to produce specially for the US.