i like the way sand looks, i have a gravel tank with a sand pit. something that can be tricking with sand is cleaning it and not sucking up a bunch of sand while siphoning. in regards to your plants, i wouldnt just change because your getting plants, IMO it does not make that much of a difference to the plants. IME it is easier to plant, plants in gravel, also if you have a decent current in your tank and want to plant, i would say stick with the gravel.
have you considered mixing you gravel with sand? depending on the desired look you want, add more or less sand... i have seen some FANTASTIC looking mixed substrate tanks. also they sell sand that is a little more course that might be a great option for you.
-also they sell substrate that is sized smaller, that is ment to be mixed with your substrate (floramax and flourite are both good brand IME) they help your plants grow aka fertilizers
***PLEASE PLEASE PLEASE make sure you get sand/substrate that is for freshwater tanks, the live or marine sand can wipe out your whole tank stock, i have heard of people making it work by soaking and rinsing... i gave it a try once and i lost my stock :/