You could use wheat malt. Weyermann pale wheat malt has a diastatic power of >300 WK. 2-row is 140 WK. I think wheat malt should have no trouble converting starches. Just be prepared to use a lot of rice hulls.
Jim Spencer on Basic Brewing radio has made many batches of 100% wheat as well as 100% rye. With the addition of a crap ton of rice hulls in a BIAB set up both can be done BUT the 100% rye will be a goopy mess regardless.