Anthias

i think the only "red" one is a lyretail. The fiji one is the "redder" of them, being mostly red. Indian ocean ones are kinda red but moreso red/orange/yellow combo. I had a indian ocean one and it wasnt quite "red" more the combo of red orange yellow, so if your looking for a mostly red one try to get a male fiji lyretail.

4 in a 75 may be a bit cramped if they are adults/full grown (5ish") but if they are small you would be ok for a while but they would probly appreciate more room to swim eventually as adults. maybee someone that has had a group of them will chime in on that as the most ive had in my 100 is 2 adult size and they were quite active.

Lyretails are one of the easier anthias in terms of feeding i believe, so pod population wouldnt be a determining factor with them (vs the pickier anthias and say a mandarin), they accept prepared food well. the lyretails i had ate quite well on anything i fed the tank.

just my .02

 

If you have multiple females, one will turn into a male over time. Depending on how old/young they are, in about 2 months (could be more, could be less) one female will start to turn into a male. Transformation takes around 2 weeks generally. Again, these are give-or-take time estimates.

 

Liveaquaria would probably be the best bet, (but kinda sucks since u can't see the actual fish unless its a divers den item)I haven't seen any all red ones at local stores, they could possibly order u one tho

 

Lyretail & dispars are the two hardy species. Lyretail will be the darker red one.

They do need to be fed quite often when you first introduce them, especially small foods.

75 may be a little on the small side, but if you keep 2-4 and nothing else you should be ok.