Get the 200 mph monkey off your back with the Screamin' Demon.
Anyone can spend a ton of cash on a state of the art ARF speed plane and do 200+, but I fail to see what that accomplishes at this point...?
It's your money, your time....I'm just rendering my 2 cents worth.
As far as what really counts [pure enjoyment], I'd build a slightly larger delta [or lengthen the one you've already got] and just have the time of my life running 0-5% nitro through that engine with a less aggressive prop.