Hi Lewis, welcome to the forum!
Unfortunately, there's not a lot you can do to get mega power without spending £k's. However they're are some cheaper options to extract some more ponies, which could see you to roughly 145/150 bhp:-
I would do the R32 DSG airbox mod (have a search for this) along with a panel filter, exhaust, maybe a sports cat (if they do one for your application & budget allows) & then finally the re-map to optimise all your extra goodies.
Then next i'd look at the suspension options + the Eibach rear ARB & maybe the 312mm front brake upgrade to improve your 'point-to-point' pace.
