Guess it might help to update this, it did progress quite a bit while I wasnt looking! Hehe.
I did end up trying this out. The epoxy I used is a two-part expoxy called Envirotex Lite. I bought the one gallon kit, which cost me 90 bucks, and use 3/4 of it mixed with sand to put a 3/16" or so layer on the bottom of the tank. I also sprinkled alot of sand ontop of it. It leveled out, hardened, and made a perfectly flat sandbed look. My mom wanted the sandbed look, I wanted the barebottom effects. I have yet to see any corraline growth on the bottom(has been up for a month) but I also have cyano on the bottom.... I guess it would help if I had my skimmer finished, lol. Syphoning off the bottom is quite easy, I can syphon crud out really well, and you dont suck up all your substrate. The rocks stay in place well, the glass is protected, and I get the sandbed look. I will update again in about a month when my cyano should be gone, lol.
So far I love this. No problems with it cracking the tank like I heard happening with one guy. The sand stays down fiarly well, its hard to get grains loose.
Here is a pic of the tank. It looks bad haha, but were talking about the sand. Tank looks better now though.
Hope this gives a little more insight for all of you thinking about this.
Chris