Hi mate,you need to do what's called "direct access" which basically means the test is a bit harder and you learn on a 500 cc plus machine,but once your successful you can ride anything you like,if you take your test on a 125 your restricted to 33bhp for two years after you passed your test.you say get a bike again so have you already passed some form of test?if not you may have to do your cbt first just to ride on the road but that's easy peasy and won't take more than one lesson.know what u mean about a gsxr,lovely bikes,there was a cracker in the for sale section on here not so long ago?