Hey man, you shoulda posted this in the Gluten-Free forum; I just found it because I'm putting together a gluten-free white IPA recipe right now and was looking around to see what people did for hops.
I've done a successful IPA with 3:1 sorghum:candi syrup, with lots of citrusy hops (Cascade, Columbus, Centennial) and some grapefruit zest, and all my non-GF friends tell me it's awesome (I think it's too spicy). I've heard nothing but good things about the Briess Brown Rice Syrup, so my plan is to use that (get it at highgravitybrew.com) instead of sorghum, or maybe 3:1 rice syrup:sorghum syrup. Plus maybe 1/3-lb per gallon of candi sugar (or just regular invert sugar). I always add about 1 oz maltodextrin per gallon of wort for mouth feel.
Not sure how to get a similar effect to adding wheat...steeping some gluten-free instant oats might do the trick, or maybe some quinoa. DON'T use buckwheat, it will add a deep earthy flavor not appropriate for a beer of this style.
Also FWIW I brewed an 8% ABV double IPA with almost all chinook hops, using 2:2:1 sorghum:rice syrup:amber candi syrup, and it's f***ing delicious. I think I added about 4 oz of maltodextrin for my 3 gallon batch. So yes, it totally can be done!