As dj says, you will be fine without a map to start with, but if you can stretch to a map then that will get the best out of it, you could go for an esl, apexi or similar, for not much more than around 400 quid.
I would imagine your car will be the same as mine with regards to sensors etc, you should have a cat on fire sensor in your current downpipe, which you just disconnect and blank off with a blanking plug in your decat downpipe, your lambda sensor should be in the headers.