Great choice with R-Tech, Nick really knows his stuff.
For Stage 1 just a check is fine. PCV and DV as mentioned. Should see a healthy 250BHP plus a nice smooth liner graph. Will drive like a new car.
If want to, can do a pre cat removal (know the pre cat out before cat) still passes MOT and helps turbo spool up better, adds about another 5BHP for the price of a downpipe gasket.
With you induction will help also.
Let us know how you get on. I can't wait to book mine in with Nick