I've owned a Phat 1000 for quite a few years, and was quite happy with it, although the screen ghosting is very noticeable in some games (FFIV complete collection springs to mind as one of the worst), and some of the better emulators don't work perfectly - the NeoGeo emulator has trouble with some larger rom sets for instance, but it is very comfortable to hold, and can be had very cheap.
Last month I bought a PSPGo with some Amazon gift cards I had accumulated, and it's one of the nicest games machines I've ever owned, tiny and beautifully made, the screen, though a little smaller than previous PSPs is stunningly sharp. I'm running 6.20 PRO with the perma-patch, but I bought the charging cradle too and never turn the thing off, I just sleep it and stick it on the cradle. Also, if you get the component cable and a PS3 controller you can play all your games on your big TV, honestly the quality isn't great, but it does actually upscale PS1 games which makes it preferable to using an actual PS! with an HDTV. Only minor niggle if you're just learning your way with PSPs is that some older games and some plugins/homebrew fail to "see" the internal storage and won't save, this can usually be remedied by installing an M2 card though.
I'd say get a beat up but functional 1000 to learn your way around CFW (zero risk with a Phat) and get a Go for the best possible PSP experience.
BTW, I have pretty big hands, but after some initial confusion caused by being used to the Phat layout I'm now quite comfortable with the Go's controls, and it weighs nothing by comparison to its big brother.