Lee Ah Loi Sensei (7th dan) also has video tapes. Her second tape would show 6 katas I think. In UK its distributed by Beckmann home video - meadow court, west st, ramsey, isle of man, british isles. Tel 0624 816585 and fax 0624 816589.
Personally I didn't think much of her 1st video but the second one is much more interesting. But you probably would have to know the individual moves first as they don't really teach you the fine points (and besides, aikido is learned on the mat not via books and videos). The video would help in showing you the sequence though.