I have very similar mods to what you have suggested except I have long tubes. Dont waste your money on the shortys, go with the long tubes. The long tubes were the single biggest power improving mod I have done hands down...
I'd figure an increase of between 20-35rwhp with the parts listed. Now for the tune, some people pick up tons of power others don't. I for example picked up 1 rwhp peak NA. Now that doesn't mean I didn't pick up power. I have an increase of 9hp below the peak and a 10flbs of torque increase across the board. Which makes the car alot more fun to drive.