Ooh - welcome to a world of choices and possibilities
I'd agree with Amanda @gilbertandmartha that having a smaller living space isn't going to be a problem. A bag hanging on the back of a door - perhaps in the bathroom would be a good idea.
With my little one we had him in bumgenius nappies from about 8 months old and he was quite slim, so I think one-size might be the way to go for you.
Amanda's suggestion of trying a few different types is a good idea as it'd be a shame to buy a huge set of one brand and find out that they don't work for you. Second hand is also a good way to get some at a decent price too
I'm a fan of the weenotions basic PUL nappies too, as without insert (which you will need, but I already had loads of), it came to about £37 for 6 nappies and the quality is great.