I have a 40 gallon (4 ft long) tank and would like some stocking suggestions.

My current tank inhabitants:
*2 marble hatchetfish
*3 neon dwarf rainbow fish
*1 golden bristlenose pleco
*1 female endler
*6 dwarf chain loaches
*3 amano shrimp

I lost 5 dwarf chain loaches and a female endler from the ich. Fortunately, fingers crossed, I think the ich is finally gone. My problem now is figuring out what to put in there. I have been trying to acquire more neon rainbows and marble hatchets for months now, but it seems like most of them die shortly after arriving at the LFS. In fact, it was a hatchet that gave the rest of my tank ich.

Any suggestions on what else to put in there or take out? The pH is usually 7.2.