the sand i use is easy to clean. i have a 20 grit sand in my tank, so the gravel is still kinda heavy so not that much gets sucked up. As for the pleco, as long as you have places for them to suck on, then you'll be all right. as for thr color of sand for cichlid's, alot of people will tell you black sand with a black back ground. i like the "Natural look"... It's all up to the person and there theme.
When I had sand I ended up using the vac every couple of days because I could see the poop. I didn't go deep ito the sand, just the surface so that the mess would be cleaned up.
I have play sand in a couple of my tanks. I have no problem cleaning it or loosing it through the python. It will suck up if you stick it down in the sand, but when you lift it out and up a bit it all comes back out. When I "clean" the sand I just hover it over and suck up the icky stuff. I do stick it down in the sand at times and stir it up a bit that way. With the sand you do want to stir it a bit once in a while, or just stick something down in it to so gases do not build down in it.