Sam - if it has been lifted find out exactly how it has been done (that's if you are interested in buying it) as if it isn't done correctly it can cause terminal damage
Only the back has been done? As far as I have been told as long as the alignment of the rear axel and diff to the prop remains the same then you can go upto four inches. ie. the rear axel will have to be tilted backwards over as you lift it higher so that the UJs on the prop don't wear out.
Ask how much longer the shackles are and see if there are any spacers between the rear axel and spring. I haven't really heard of many issues with the rear being lifted it's the front where the main problems lie. PM sent Sam.
Of course, but don't let that stop you. They told me I was mad to get a classic panda for my daughter, didn't stop me and she loves it now she's passed her test