Having run Sunbeam Lotus and Excels, I can say that they are both great cars. You will need to try both to really understand which one suits you best. From a budget point of view, you will get far more with an Excel as a really good one will be half the price of a good Sunbeam. Engines are very similar, of course, and almost identical in effect for late Sunbeams/early Excels, and both can be modified from standard quite easily if that's your thing.
Excel is obviously much lower than the Talbot, so that might have a bearing on both access and how the car feels. It also affects tinkering with the car; I hated doing anything on my Excels.
The Lotus will ride better as standard but improvements can be made to the Sunbeam, which is a bit soft in factory spec. Driving both cars is a joy; I found throttle reponse on the Excel not as good as a Sunbeam, though. Interior ambiance is obviously different, especially if the Excel is full leather.
Rust is naturally the tin-top's enemy, whereas the Excel is more likely to suffer paint issues such as lacquer peel.
Of course, if you have a proper Sunbeam Lotus budget you could look at an Evora, which I can attest to being a superb car also.