Which Brushless motors ?

Right now i'm using an HVmaxx setup with two 6cell 3300gp's. My truck weighs a tad over 9lbs with batteries installed. I've been racing it a bit at the local track but I have only Nitro's to compete against. The A mains run 15 minutes and what i'm wanting to know is what would be a better brushless setup to compete with these nitro guys. If i gear the HVmaxx for longer running, i can't keep up with them, especially on the straights. They get to pit but if i pit to change batteries, i lose. Is there a system i can replace the HVmaxx with that will give me the runtime I need for the A main and the speed to keep up? I'm soon going to be getting a set of the Intellect 3800's and will most likely use 14cells. I'd like to stay around $300 -$400 mark for the brushless.