Lots of places have them, minispares, PLminis, minisport you could try your local breakers but that's a long shot. Put a wanted advert on theminiforum forum somebody local may have one.
I have tonnes of spare dizzys (5 or 6). You will need to get it set up at a mini specialist on a rolling road to get the right spring and generally fettle it to be the best it can be. I have a few lucas ones and even an aldon (i'll probably use the aldon for my build).
Reply if you would like one for cheap and i would be looking at about £10- £15 with postage of £4.20. I can get you the best one if you tell me if your engine is A or A+ and whether you want the contacless electronic one or the mechanical contact breaker one.
Oh thats good, saves buyin a new one.
I don't know of any replacemant bearings for the water pump, but it may be worth just getting a whole new one, minisport sell them for £16 inc vat.