Mike
This really is a very broad question and there are no simple answers.
I am no expert on the Series 1 4/4s but there are many here who know them far better than I and I am sure they will correct my errors.
A pre-war 4/4 (not 4-4) will have a Coventry Climax engine about which there is a lot of knowledge and expertise, but apart from service parts, availability of spares is going to be an issue. Some are available, others may be trickier. The Moss Gearbox is also well known both inside and outside Morgan circles and here the spares are slightly easier. Likewise the rear axle, but don't expect any of the big items to be cheap. You will also need a certain degree of mechanical "sympathy" with the car to get the best from it. The cooling system, is thermosiphon (although some modify with an electric pump) so cooling issues can be expected if used in traffic. The brakes are cable operated on early cars , and these need to be very precisely set up to give adequate stopping power, once done they do work quite well. If the suspension is in good working order the handling is delightful and will put many a more modern car to shame,. almost infinitely "chuckable"
If this does not sound like your cup of tea then the Ford crossflow engined cars from the 70/80s are great in their own right. They might not have the charm of a Series 1 , they certainly won't qualify for as many historic events, but now you have hydraulic disc brakes, much more comfort , much greater availability of spares, and a much more powerful engine fully cap[able of keeping up with modern traffic.
The choice is very much up to you, If the idea of a Series 1 sounds 'romantic" but you are not sure of your suitability as an owner I would tend to recommend the later car, if you regard the early car a great challenge that will keep you on your toes , then go for it.
AS ever go for condition , condition , condition , and is is best to take a Series 1 owner along with you to inspect any potential purchase.
