first loaches are just fine in a planted tank. My neighbor and I both do planted tanks and she has 5 inch clowns in hers, as well as yoyos and kubatias (sp?)
her glosso is a loss, but everything else is fine.
don't use tahitian moon sand. first it will just fall to the bottom eventually since the eco complete is bigger grained. next until it does, it is very sharp and not great for bottom dwellers. use all eco or consider mixing eco with flourite (tho rinse rinse and rinse the flourite more) its a nice look but not nearly as easy to set up as all eco.
if you want some of the plants mentioned here, like cabomba ect, you need high light, 2-3 watts per gallon minimum. And you shoudl consider co2 injection or at least adding flourish Excel to the water daily.
If you want a lower tech/lower maintenance tank you can do anubias, java fern, even ludwiga repens and the loaches and plants will be fine.
check out
www.aquariiumadvice.com section on planted tanks
and
www.aquabotanic.com for more advice on how to set up a planted tank.
the clowns will be fine.