Hi Mate,
the ampage sounds about right for this one, i have bought a new battery today for my a4 1.8T today, what a ballache trying to source one for a decent price (halfords and stealers wanted £100+), eventually i settled for the Bosch S3 70ah which is recomended. I needed one as the original was still in the car and has been a bit slow starting over the cold period we have had plus the indicator was totally black which is not good anyway. I got it from GSF in the end and cost me £69.33 with the 3 year warranty. There is a download available on the Bosch website and it tells you all the dimensions the 'S' series batteries which i found helpfull.
Hope this helps.