Thanks for reply, but right now I am not planning to change IB for any other broker. I'll write to eSignal support and check if they are able to properly execute spread/combo orders for IB.
It depends on the type of product you want to trade. As far as I understood every charting software has no problems sending orders from DOM to IB for outright futures, but pretty much none of them will send future combo/spread orders to IB. although those combos are listed/traded directly on exchanges and should trade like any other futures contract.
You should check CQG and TT though it does require a new broker. I am pretty sure they will give you DOM for the spread and the ability to send a spread order.