I have been using the Body Glove case for a Sidekick LX. Fits snugly with the Otterbox cover on the N900. Velcro closure is not a problem for me. Something on the Otterbox sometimes gets caught in the case. I have to do some experimenting to find out what.

If you buy it from Amazon watch out for a seller with a very low price. IMHO they have their inventory messed up. The wrong item came, but they provided a postage paid return and gave me a full refund.