Usually I never refer to my own typefaces, but I think that "Andrade" might work.
http://www.myfonts.com/fonts/dstype/andrade/

Good call Dino.

http://www.myfonts.com/fonts/storm/walbaum-text/

Or if you go a bit earlier look at Baskerville Ten and John Baskerville from Storm.
Tim

I do quite enjoy the lower case "g", but I'm looking for something a little more distinctive in the uppercase department.

Thanks for your response, I may suggest it to the client.

> I’m one of those dreaded “Graphic Designers” who ...

If you're here, then you're not. :-)

I thought your brief, although interesting, was a tough
call with that "G"/"g" requirement, but Andrade actually
seems a great match! The thing is, if you think that "G"
is not distinctive enough, I think I can safely say that
you won't find exactly what you're looking for, basically
because it's very hard to find a funky UC "G" in a reserved
design like you'd like...

But here's an idea: find a font that's as close a match as
you can find but without a funky "G", and get a designer
-preferably the original one- to funketize it for you.
Or actually, since it's for a logo and not text, you can
just funketize it yourself! Just show us your work-in-
progress so we can tear it apart first. ;-)

Or what about this (from another current thread actually)?
http://www.optimo.ch/pages/departement/index.php?id_categorie=1&id_font=9

hhp

See if Letterhead Fonts has anything you're looking for.

http://www.letterheadfonts.com/

Thanks for your replies all. The art director agrees that Andrade is currently our best choice, perhaps borrowing a flourish from the ligatures to embellish the uppercase G. Quite an improvement from some of our original choices. We're going to be running it by the client to see what they think. Since you're all interested, I'll be sure to let you know where it goes.

P.S. I wish myfonts.com gave you the option of kerning — or at least tracking — previews.

You could also check out De Vinne, it has a nice G.

http://www.myfonts.com/fonts/bitstream/de-vinne/

caslon IV sans
http://www.orangeitalic.com/caslon.shtml

despite what it says on the site, i believe this typeface is available for licensing. alternate g and G too!