I do layout for my magazine and looking for something portable when I'm not home.

Used instead of new would be preferable as there are much faster laptops than mine for $1000. In my office I use an '06 iMac 2GHz Intel Core Duo so anything made in the past 5 years will blow it away.

Should I get a newer, faster 13" and rely on an external video source for the large screen or get an older and slower 17" without the need for the external monitor?

What are Macbook Pro's best years for reliability and durability? My PB G4 from '03 is still going strong (except for the busted screen).

Thanks

I'd go with the more modern 13-inch. It'll guarantee longer-term compatibility with accessories and make it much easier to stuff in a bag. The 17-inch isn't that heavy for its class, but it's like shoving a big dinner tray in your pack. You wouldn't really want to use it in coach class on a flight, that's for sure.

Get a 13" MacBook Pro from Apple's refurb store. Best deal all around, and suits your needs. New battery, looks new, full warranty.

13 with an external monitor.
17s too big to travel with.

I would recommend something with lots of screen "real estate" wait for the retina MBP!

depends on what you use it for, if your're just writing then an macbook air, or macbook pro 13"