Here is my 2c worth.
If you are lacking time, space, money and or skill level then I would say:-
Sell two, and just concentrate all your efforts on one mini.
Otherwise you will always have three cars that need work.
You have said all you want is a nice mini.
You didn't say you want three minis.
I guess you would have to decide if that is your daily driver you do up, or the full resto job on the 66 Deluxe.
The deluxe would be a long term project, and you would need something else as a daily driver ( I would recommend a cheap Diahatsu charade ). Running a mini as a daily driver and doing a full restoration on the deluxe at the same time would be very demanding on your resources (time, money, effort), as I'm sure you have already worked out.
Doing up the daily driver would be the easiest option for you at this point in time. You could make it a very nice mini if you wanted to, just by putting all your effort into the one car. You will have a nice mini, and it will be drivable now, not after the long wait of a full resto.
The deluxe would probably end up the nicer car, but a full resto is a huge thing to take on. How much patience have you got?
Decide which one you want to keep, then do it up to be one very nice mini.
Later on down the track you may find that you have greater resources, and perhaps the inclination to have more than one mini, or even other types of cars, but it you spread yourself too thinly now you will just end up with a heap of undrivable cars taking up your front yard.
I am speaking from experience.
I had five minis at a time when I first started playing with minis, and it was just too much to take care of. So I sold all but one, and poured all my efforts into that car.
I took it on rallies, including the Classic Challenge, took great pride in showing it off at car shows, and always joined in cruises. Great fun, and it was good to be able to have the time and money to fix anything that went wrong.
Now, later in life, I have more resources and am able to indulge myself with more than one car - but stretching myself to thinly is still a problem I have to watch.
Cheers,
Ray.