probably not because most of the decent arcades offer these products in addition to bonds & commodities already.
An arcade specializing in stocks and DMA CFD's would be severely limiting its potential clients to just a small niche. Remember that one of the big advantages of arcade or prop shop environment to the individual trader is to benefit from ultra-cheap fee's - the arcade can only provide low fee's if it can collectively deliver large volume to the principal clearer (ie: Fortis Bank, Man Financial).
An arcade that does decent volume in fixed income or commodities will have buying power to get cheap rates across the board. To get the low rates you'd need to get an specialist arcade off the ground you'd need to be doing the volume already, or it'll be an uphill struggle - if the rates are too high to start with, you wont get the traders on board that you need to increase trade volume and bring the fee's down. catch 22.
