Not sure if I can give any good suggestions for you or not. My baby is 13 and I can't remember what he was interested in (other than baseball) at the age of 7 or what he even liked! But here goes:
1) Disney books on tape - what child (and children at heart) can resist a Disney story or movie
2) Look for some cd's of songs where kids are signing them, not the artist who originally recorded the song.
3) If you have a Discovery store (or science related store) near you, see if they have any "hands on" type game/toy. By touching and feeling, exploring with his hands, it may help him "see".
But I'm sure whatever you select will be appreciated because it will come from your heart and there's nothing more special than a gift from the heart
You may also want to try to find books in braille for the school he attends. If it's like any other school, gifts/donations of any kind are always welcome and appreciated! Please keep us posted on things if you can - RJ just might be your "angel on earth"!!
Suzi