With your name you should fly in! Seriously, though I tend to agree with the doubts raised about a Cursor for regular commuting, they are very low and minimal. Good fun, but...The thing is that if you add more power you need to improve brakes, this adds weight and puts more strain on the structure so it becomes heavier and needs more...etc!
In many ways a modern car would be a better choice for regular long-term use, and I say this DESPITE being a big fan of classic micros. I have a 1963 Trojan which I restored from a wreck. I drive it around London and have done longish trips to Staplehurst, Medway, and Faversham, Kent, including M2 and M20. Frankly I would not want to do a longish journey every day.
A Bond Bug might be quite a good choice. Its 4 cyl engine can easily keep up with traffic and it will keep out much of the bad weather. You might need to pad up the seats, though! They are definately "classic", vaguely "micro", and can be reasonably reliable. A small Fiat could be good, or a Goggomobil. What about an old Mini?
Whatever you decide to look at I think it is fair to say that few classic micros (if any) are used nowadays for regular commuting, so you should bear in mind that the novelty might soon wear off!
Of course it depends where you live and work, what the roads are like, and most important what the traffic conditions are like. If you really want, and can afford a genuine classic micro, then for your needs it really has to be one with a good club, spares and support. For that I would suggest Heinkel-Trojan, Isetta, Messerschmitt, Goggo etc. Good luck, let us know what you deciide!