I have a RIMS system and continuously recirculate and make wheat beer all the time. I just add more water to thin the mash. I use about 4-5 gallons for a 5 gallon batch. After I mash in for an acid rest, I wait about 30 mins to start circulating. After the mash seems to be recirculating well, I start my heat. Works the same as with other beers for me. I only used rice hulls once and didn't see much difference. Pay attention to how you crush your grains. If you wet them a little before milling, it leaves your hulls more intact and makes for an excellent grain bed.
If your still worried you can try this also. Take about 1/2 to 3/4 lb of barley and mix all your wheat in a pot with enough water to mix a thick mash. Mash this combo in at 120ish and continue to heat to 152 and rest for 15 mins or so, then continue to boil for about 20 mins. Add this to your other grain that you should dough in about 120. After it is is mixed well and stabilized, it should be pretty close to your Sacc. rest temp. Start up the pump and adjust your heat until you get to where you want to go. Boiling the wheat before adding it to the mash really thins stuff up. Kind of like a single decoction.