Holiday photography gear?

I know this has been asked 100 times before, so please bear with me.

For an upcoming holiday in Italy, I'll be photographing food, architecture, street (people), the occasional night shot, and otherwise taking holiday snaps.

I have a Nikon D40 with a few lenses at the moment. Autofocus isn't important to me.

Considering:
Nikon 20mm f/2.8 lens
Tokina 12-24mm f/4 lens
Sony DSC-HX5V compact camera
Pentax K-x with 18-55mm kit lens

Experiences? Can anybody recommend for/against these for travel? Do any of them stand out or is it really down to personal preference? Thanks.

Added (1). EDIT: The reasons for my choices…

The Nikon lens is fast, wide (I like wide), good quality, I could use it for general-purpose. The Tokina lens is very wide but extends to 24mm, I could use it for general-purpose lens. The Sony camera is pocketable and has HD video (though I realise it's not great). The Pentax has great ISO performance (for night, and I wouldn't need fast lens), has double my current number of megapixels, HD video and runs on AA batteries.

Added (2). EDIT 2:
Sorry, xSx, I should have mentioned… I can really only afford one of the items listed above.

Nikon 20mm f/2.8 lens… Love the wider constant aperture… Excellent for low light and every situation basically~ ^^

The Pentax for four reasons - it has a higher megapixel count, you have a greater zoom range, it has HD video capability, and can be powered by the AA batteries that can be found just about anywhere. That's if you are serious about photography more than wanting a camera you can put in your pocket. For travel that might be more important to you. You have to decide. If it was me I'd take the Pentax and leave the rest at home. I'd also thoroughly test it before relying on it and finding out you've lost precious memories due to a malfunction.