Check http://www.elitetrader.com/br/?action=view&R_FirmID=284 DeepDiscountTrading which clears with Crossland.
I use a guaranteed IB of Crossland ... Deep Discount Trading. I get great service days, nights and on one occasion over the weekend. The Crossland deal is straightforward. Good commissions and margins and no nonsense. I use these guys and IB. I like the sweep into the SIPC account IB offers and I like the low margins at DeepDiscount/Crossland.. The combo is ideal for me. See the DeepDiscount reviews here on ET and click through to their site.