Doubt you will find one with AC - I don't think any mk3 diesels had this option until 97 at the earliest - would be way more than £1k if any has it. (it would be a TDI GL) - They will all have PAS
the basic 1.9d is horrid slow
the 1.9td (sometimes called the Umwelt) is horrid too - quicker than D, but much less economical
1.9TDI (90bhp) is a peach - it is more economical than the other 2 and much much faster - from 1994
Go for a TDI, but you will struggle to get a decent one for 1k. Make sure it is a real TDI, some people think TDI is a generic term for all diesels and advertise a non TDI as such.
Cars post 95 have colour coded bumpers.
GL is a very nice spec - amost looks VR6ish
CL is ok spec
Tend to be reliable, but you will be looking at 10+ year old cars. Even the nicest one can sting you for £200 for brake lines, £200 suspension bushes / shocks etc etc.
I have owned a few of them - I ran them as 'bangors' whilst renovating houses and I got away with zero depreciation and low running costs. Buy a genuine one that has been well looked after by a low number of owners. There are still some really nicely maintained sub 100k 1995 TDI's around which have been in the same family since new - budget about £1500