It's interesting you mention Hunstanton, considering I live in Norfolk and have done most of my life... used to go down there a fair bit, to the arcades and do still, now and then. They still had an original Track and Field cab in one of them last time I was down!
Going to Insert Coin 09 this Sunday - giant arcade expo... there's where I'm collecting my new cab from!

They are going to have 100's of cabs set to freeplay, it's going to be good!
To be honest, sites like the one you hyperlinked aren't the best place to get cabs from. They are fairly cheap reproduction and original cabs can be picked up at a snip of the price - plus they are authentic! Nothing like playing the actual Mortal Kombat 2 cabinet you played as a child!
Oooh, difficult one on which to go for on the retro handhelds... I have all 3 and I have to say, the most classic games are on the Game Boy, though the Game Gear looks nicer and can play Master System games as well with the right adaptor! But, I'm a massive Neo Geo fan and say that has the most appeal for me... probably the niche factor!
Haggler... haha, I know the rules of emulation!

I have a lot of boxed stuff... I have always been more of a collector than a player in some aspects... not to say I don't enjoy playing but I've probably enjoyed collecting just as much if not more!
It's going to be a tricky one to decide what to keep and what to flog. I need to be fairly ruthless otherwise it'll be a pointless exercise!