Hi mate welcome to S.O.C
Nice choice of car (clearly from a complete bias view) ;)
When I changed the Blobeyes rear spoiler from the WRX I didn't need to do any drilling at all swapped over, I did put some silicon over the holes though, but I went with buying one that was already sprayed my colour from a breakers. Had a few marks as you would expect but still look's great IMO :)
So that's the route I would recommend I was searching for a few weeks, and all in was about £280 with P&P. Still think it was cheaper then getting one sprayed, but I don't know anyone who does that :D
But if you really can't wait or have the time to search then I'd say be as good as any spoiler really. Any problem I have found with these types is if the break light bulbs go in the spoiler is replacing them.
And please feel free to have a look around and join in on the threads, great bunch of people on here that are happy to help and have a laugh.
:D