I doubt you can fit the XR2 carb and even if you could it would need rejetting to work with your engine.

PowerBoost valves are complete shit. Fullstop. Wouldn't fit one to anything ever.

I know it's not what you want to hear but yuo are not going to hike the power from this motor. Even spending a small fortune you will still be left with very little additional power. Save your cash and change the car, it honestly is your only sensible option.