As said above there also the 306 to consider, when i was looking the insurance difference to a 106 was minimal, they handle just as well (less chuckable but they have the ride that makes it feel like your driving a much bigger car and as such are more comfortable with 70mph on the motorway) really and in 1.9td or 2.0 diesel form are reasonably nippy and economical.
Give them a shot too, some have them have a lot of goodies and snazzy bits 106's wont have.
But i would say if your getting a first car you cant go wrong with
A 306/citroen xsara (same car)
a 106/saxo (same car)
a fiesta 1.25
All are great, dont write off a mondeo either, you can get some silly cheap quotes and they have a lot of comforts if you fancy a long journey.
With regards to a fiesta 1.25 or mondeo the main thing to worry about is the rear arches and sills on them
thats how they end up going in the end so one with minimal rust is always a good thing.
This is a much smaller issue on the 306 / 106.
Peugeots of that era seem to fight rust well, my 306 is 12 years old this year for instance, the only rust i can find, (ive seen underneath it on a ramp) is in the engine bay and its very minimal.