For a sub 1k car you're going to struggle to find anything that is in great condition, so you're going to have to accept that it's going to be a bit grubby, paintwork is going to have scratches and so on, it won't be shiny and perfect. For a sub 1k car you're likely going to have to buy into things like taxing, MOTing, tyres and some mechanicals required. So long as you can live with that and are happy that for a cheap run about then happy days.
I recently did the same sort of thing with a 147 for the wife's wedding present.
I went out with £500 looking for the best looking car I could find and as long as it ran I'd be happy. I found a car eventually that was cosmetically okay enough, still has some scratches and marks etc but polishes up shiny enough. Since purchase though I've had to deal with gear linkage bushes, selector housing, selector cables, handbrake cables brake switch and airbag issues. I've also replaced the entire interior. It's spot on now like but required the effort putting in to bring it up to where I wanted to be.
So long as you're prepared for the same you're laughing.
1999 156 1.8TS Sport Pack 3
2001 166 3.0 V6 24V Super
2003 156 GTA 3.2 V6 24V
2005 156 1.9 JTDM-Jet Sport
2008 159 1.9 JTDM Lusso
1997 GTV 2.0TS Lusso
2001 147 1.6TS Lusso