Do they have to be 50g or 2 oz. tins? If they can be 8 or 16 oz., I'd probably just stock up on a variety of G.L. Pease blends that come in those amounts.
As things currently stand, I don't even have a hundred tins (even if you include jarred bulk), and there are very few repeats. This is because I'm a guy who A. loves variety, and B. is newish to serious pipe smoking and tobacco collecting, and C. doesn't know exactly what I love and could smoke for the rest of my life.
But now that I've smoked quite a number of different and excellent (and some mediocre and not great) tobaccos, I again would say that I'd go with G.L. Pease, definitely with an emphasis on Quiet Nights. I'd probably also stock up on Super Balkan and MB Scottish Blend as well.