I am going through the same exercise right now (on a largish tank). My tank is also 30" deep, and will be in wall inside a fish room. What I have done is to purchase a 4 x 12 panel of FRS grating and I have cut a 2 x 10 piece that will be a walk platform for me to stand on and lean over the back of the tank.
To make it easier to reach the bottom, I have been thinking about using the remaining FRS panel to make some platforms that would be raised about 4" off the bottom of the tank using 4" PVC fittings. I would camouflage the edge of the FRS with some branch rock, and place large live rock structures on it along with small individual pieces of LR top create a false bottom. The expectation is that this will allow my sand bed to stay quite clear (with Gyres in use) and give the fish plenty of extra swimming space under the LR. Visually it should not be too obvious as the platforms will only be 2 or 3" above the sand bed once the sand is accounted for. The PVC fittings will also have some holes drilled in them to do double duty as fish condos.
The only concern about this, is that any dropped frags will become very hard to retrieve if they fall through the grating.
Dennis