Lol, have a search on both this forum and other golf gti forums regarding ChippedUK, and you will see for yourself what troubles you will get yourself into!!
....
Revo and Superchips have the best reputations.
Chipped UK do not have a good reputation though I personally have never used them.
...And APR!
Superchips have had a few minor problems here and there too, however their customer service is great, so any problem is swiftly rectified.
P.S. Stay well clear of ChippedUK.