How far's the ride to work? Anything over a few miles and you'll not want to be riding a cruiser.
For the track and trails (and seeing as your a fat barsturd like me) I'd try and find a SX devo24. Full cro-mo and light-weight. The only problem is finding a good one. They do tend to have the odd dent here and there (from the factory) and as you'll probably have to get it from the USA, sending it back is not an option.