Just for clarification, you meant my "Torque300" tune and the Exige power recipe setup and not the REV300 (you said rev in your first post)?? The latter being the non-intercooled TVS blower....
The Rev300 won't be a step up in power, it will just be a lot simpler maintenance and lighter-- in addition to being upgradable to the 400. The REV400 will be a big step up in power.
Now if you're looking at the Exige power recipe type of deal along with Torque 300, then it will be a bump in power from what you have now. Can probably fix that funky stumble you've been posting about as well.
Just depends on your power goals...
BTW- do what you want with the balancer, but be warned that replacing the oil pump gears isn't something you do "just because you're down there"! Balancer is an easy job. Oil pump requires removal of front cover, wihch means front motor mount and purch comes off the frame, which means coolant is drained, which means oil is drained since coolant gets in it, which means timing chain comes off, which means you need to retime your cams, which means your reluctor ring comes off crank, which means your small sprocket comes off crank, which means you THEN FINALLY get to the oil pump... Now, you have all those things to mess up when putting it back together

... If you're handy with a wrench, then more power to ya... just a heads up. there's a bit to it
-Phil