hmm it depends what YOU want.. i would never buy a N/A car over a turbo one.. im just too used to driving turbo'd cars.. to be honest though £1500 is going to be a nailed S1 id be surprised if the dorrs were hanging on by much more than a rusty spot weld!
and as for the 16i its not exactly expensive.. i remember my mate had one about 2yrs ago... that 'looked mint' and he sold it for £1300 IIRC however i knew what it was really like under the shiney new paint