I'm biased:
... but how's about an MG?
Good GT's are harder to find, but you could net yourself a decent enough roadster - or even perhaps an RV8. Very sweet.
Rear wheel drive fun and simple mechanics that respond well to the 'just threaten it with a hammer' school of repair!
I'm two panels short of taking my baby off the road for a body restoration- but in the 11 years I've owned her, on average, she's cost less in mechanics bills than a new car would in repayments.
Economy's not to bad either (once you get a decent pair of carbs and know how to balance them every month or so) with about 30mpg round town.
As for Classic Insurance - two points, generally a car needs to be over 15 years of age, but the value doesn't matter - it simply will raise or lower you premium is all.
Average annual milage will affect your premium's cost too.
The main thing is you won't earn any no claims bonus, and any you already have is unlikely to affect your premium price... this also means that after two (or three years, I can't remember which) you'll effectively have zero NCB when insuring on a 'regular' policy.
Some companies will take it into account if you've been driving an 'average' annual milage of above 5k on a classic policy, but not all do - which is why some owners will insure on a 'regular' policy once every couple of years.
I only know this as I only put Red onto a Classic policy this year for the first time, so was introduced to some pitfalls by a nice man from the AA.