I can't advise on which models to buy, but I did use both effects years ago on a demo.
I was lead & vox in a three-piece, and on previous demos we'd found that I was a bit of an "overdub-nightmare". So I went into this demo thinking "one main guitar part", minimal overdubs. But playing a strat, I was worried about how thin the band might sound like that. I'd read about the idea of using chorus so I talked to the engineer and after he'd figured out what I meant he dialled this up: Dry guitar panned all the way to the left, chorus (mono, 100% wet, ie no dry signal, minimal chorus) panned all the way to the right.
We LOVED it the minute we heard it, and proceeded to use it like that through all playbacks during tracking. Then the night of mixing, the engineer told me he'd been thinking about my original requirement - thicken it up - and he was a little worried about the chorus effect, had we got used to the "wobble" and weren't noticing it? And he offered me another option - pitch shifting. Dry guitar panned all the way left, detuned version panned all the way right. Rest of the band couldn't hear the difference, even a blind A-B test, but I could and in the blind test chose pitch shifting as better - so that's what we mixed. (I think the detuned version had a slight delay on it as well, again, 100% wet, no dry "undelayed" signal)
So, my preference would be to pitch shift - unless I actually wanted the modulation "wobble" of chorus ("chorus" is a moving pitch shift anyway - I don't know, but are there any guitar chorus pedals that allow you to switch the modulation off, and just use it as pitch shift? You'd have the best of both worlds then :D).
By the way, I agree with Spitfire, for either to fatten your sound live, you need to be able to split to two channels - so, you'd need two amps, or a stereo amp, as well as your chosen effect.
