Those three would provide a great basis. It really depends on where you want to go with the training - STAB & RZ will give you great unarmed v knife material, whilst Shivworks looks at the picture from the other persective; you're defending yourself from an assault using your own knife.
I haven't really seen any of the DVDs out there that deal with knife v knife, knife v stick, etc., as I'm fortunate to be close enough to Ray to have regular sessions with him.
It really comes down to what your goals are. Personally, I have practically zero intention of ever using a knife against another person - even if it wasn't illegal to carry one here in Australia, I've just made that personal decision (this is just my choice and others may make different choices for different reasons). With this in mind, I look for material that I'm going to enjoy training in an alive environment - the same way as someone who enjoys using a sabre for fencing isn't going to walk around carrying a sword down his pants. To cut this long post short, there is a lot of stuff out there that is tactical-this and tactical-that, but your best off looking for stuff you'll enjoy training in and that can be applied against a resisting opponent.
Having said that, let me know if you find anything interesting!!! =)