The headers will actually give you more gains than you'll get with your current set up, I should imagine. Think about it, the flow is only as good as the most restrictive part, thats the crap headers now, they're restricting the nice flow to your Berks and Inividia. I can't say i've looks at the HR headers, but on the DE they are awful, but can be changed out without moving the engine. You just put it on the lift, take off the gearbox and away you go
It's a perfect thing to do at the same time as a clutch change.