I see some well-known brokers as Hotforex, roboforex offer that kind of acount. I have never traded with it but I know Currenex account has super spread and it's good for scalper. But it has Commission.
Correct me if I wrong?
currenex used to be geared towards pro traders, not retail (don't know if that's changed). and regarding spreads, FXAll and Integral have some of the tightest.
FXAll, unfortunately, is only for pros, meaning unless you have $500K or so to open an account, you can forget it (but haven't checked recently, so if it changed, let me know).
as to Integral, it is a technology provider to brokers rather than a broker/dealer. so to get their spreads you'd have to go through a broker/deal such as RJOBrien (UK), Interdin.com (Spain), and i think if i am not mistaken that FinFX also uses them to gain access to the market. i tried Integral and i can say you get many options for how the execute engine will process your orders (if the Integral order management console is exposed, which it is with RJOBrien, but not with FinFX or Interdin).
BUT BEWARE: Integral's broker software solution can be configured by the broker to operate a B-book instead of an A-book--the former means 'market maker' model, the latter 'agency model'.
but that's the case with any such turnkey software solution. the tech providers do that so that the broker/dealers can manage their risk and protect themselves.
hence why i prefer a more transparent approach such as the LMAX Exchange even though liquidity is less than on Integral or FXAll, for retail trade sizes it is good enough, and is growing. since they are an FSA regulated MTF, i heard they are required to report key metrics and you can find those via Reuters. other non public broker/dealers do not file such data. so +1 again for transparency to LMAX.