Afro Cichlids are pretty hard to stress out, how new is the gravel that is in there and how old is your bio-media in the filter?
Removing the gravel is easy, I just use a net and scoop it out. Two things to worry about though. One, scratching the tank (dont scoop the gravel up against your glass...use common sense, youll be fine) Two, ammonia spikes, your gravel holds lots of bio-media so removing it will remove some bio-media allowing for a chance for an ammonia spike. Add some Seachem stability and feed very little for the first week or so after your change and all will be safe.
Afro cichlids love sand too, its more natural then peagravel, they will still exhibit the same sifting behavior. For Texas Holey Rock East End Aquatics cant be beat, they have some good pieces for good prices, still expensive though. It would be nice under some moonlights for sure.
I got another Hydrolycus armatus, and loving it. Im not powerfeeding to maximize growth like my last one though. Im in an apartment and I cant put a tank bigger then a 125 in there as Im on the second floor. His tankmates, are, well, hated by the .gov for no reason so they are my own little secret!