Have a search on here for the side panel cut outs, theres a drawing on a thread somewhere. Spud from Saturn fame posted them up. I used them as a guide and made a cardboard template from them, the template was slightly out but was a great starting point.
I have no experience of the ebay one's so can't comment on the quality but I would have a measure of them and make sure they are correct before making expensive cuts
That's my 2 pennys
HTH Dan