Most plants do just fine in gravel, ALL of mine (other than java fern and anubias (which have to be planted on hard-scape), are planted in gravel now)
As long as you have the correct lighting (6500k flourescent) and good fertilizer most everything you choose will be fine.
Here is a list of what I have, all good low-light beginner plants.
In Gravel: Rotala, money wort, amazon swords, anarchis, cabomba, aquatic banana, apongenton, bacopa, tiger lotus, water onion, vallisneria, hornwort
Floaters: Giant duckweed, cabomba, amazon frogbit
Hardscape: Java fern, anubias, java moss, pellia, riccia
Hope this helps!