First, the links for wifi - I just did a google for "free wifi hotspot amsterdam" - I'm not sure it gets any easier than that.
First and foremost - Google is your friend. ;)
As far as the hard drive sizes go, more is always better. RAM is equally important, but the analogy I always use is that your computer is your desk - with more RAM you've got a bigger desktop and can do more work at once. With a larger hard disk you've got more drawers and can keep lots more on file.
Yeah - basic, but i never know how techie a person is. Start at the basics.
That said, I think OS X is just useable at 512MB, especially since you've got to rely on 5400rpm drives for vm in the MacBook. Nanoseconds versus milliseconds, it's an order of magnitude different. I consider 1Gb the real base memory profile, and it runs well at that. But OS X is another animal at 2Gb - it's very fast indeed then.
But buy your ram elsewhere - their profit on ram is obscene. I think they do it for business, since they like a package price and often don't consider a few hundred dollars either way a big deal. Or maybe it's for the lazy, or the rich. I'm none of those and so Other World Computing often gets my business for upgrades.
All this said - figure at least 1gb ram. More if you can find a deal online (try
http://www.macsurfer.com)
Now, once that's out of the way, of you can buy a larger hard drive than 80gb, go for it. You'll never have enough space, especially if you do video. Figure for every minute of uncompressed dv video, you're consuming 200-300mb of disk space. And video loves big, open unfragmented partitions.
Grab the biggest hd possible, make a 40-50gb partition just for doing video work and erase the partition between movies. Easy peasy.
