Best Sites for HU for my goals?

[pocketjacks]

I am currently playing 30's - 100's mix of turbo and non-turbo on stars. I make around 5K FPP's a month and average about 1800 - 2200$ profit per month, with a winrate of ` 57%. I am curious if any of you have experience with other sites playing heads up. For example, If I play Full tilt I would get a $600 cash bonus and rakeback, If I play on Ultimate bet I heard there is a rematch button which intrigues me if you get the right donkey on tilt it seems you could make a mint.

Do any of you think it would be positive EV for me to switch to a different site for heads up?

Thank you in advance for any responses.