I am not an expert, but it seems to me to depend upon what kind of music you play.

For Blues, you probably have what you need--I would guess A, C, D, G, and E are the major blues keys, and you have them covered for straight and cross.

If you are going into jazz or classical, then you should probably be looking into a chromatic one.

Anyway you can try this link.

http://www.garply.com/harp-l

It might put you in touch with harmonica enthusiasts not in this group.

There is also a newsgroup:

alt.music.harmonica

where you might post your question

Murray