29 gal is not too small for LR/LS - you need about 1lb per gal of LR and about 4" of LS (this createsa DSB (deep sand bed) that allows for oxygen poor areas for nitrification to occur) which makes for an excellent biofilter.
You would simply add a protien skimmer to your tank and a couple of power heads to pusht eh water around.
(add a carbon filter to one power head two days every week to keep the water pristine and that's all the filtration you need.