Yep, most lfs will have it
Sand IMO is better for plants roots and it is just as easy to keep clean IMO, just hover the syphon over it and it will suck up everything, possibly a little sand but that wont matter
Nay, plants dont like alot of water movement around their roots, Although i do have an UGF in my community and the plants grow pretty hard.......
HTH
Rogan