Thanks guys. From your recommendations I'm going to steer well clear of the first one. The more I investigate it the more dodgy it sounds.
I had to ask 4 times for the mileage. The guy said he thinks the RAC would take issue the chassis and TDCi conversion - god knows why - and alarm bells really started ringing when the guy said he won't give me his address as he's "had people trying to find owt where I live". Whatever that means.
Inclined more towards the second one but could do with it having an alarm and immobilise, central locking, a stereo and some seats in the back. Or failing that, go and get a custom build from Simmonites.