In my view, the finest sans serif on the market is Linotype Syntax with oldstyle figures. The base weight is just right, whereas many sans text faces start a little too heavy and therefore look a little crude opposite a nice serif. But if you intend to mix the families on the same baseline, rather than using the sans for sidebars a column away, matching the two x-heights would be your concern. In that case, try Legacy Sans, slung lower. I assume you mean Adobe Garamond; Simoncini Garamond is a little too delicate for editorial work. Stempel Garamond is big and snappy--always my pick among Garamonds, and always with oldstyle figures. Type samples shown are all 35pt.

I suppose it is a matter of taste, but to my eye, you have several of the lowercase letters following caps kerned far too tight -- e.g. "St" in "Stemple","Ad" in "Adobe", "Ga" in (Adobe) "Garamond", and "Sy" in Syntax.

Look at "Garamond" in the first line. the amount of white space, overall, between the a and the r is about equal to the white (overall) between the G and the a. For me, that's as tight as you want with a lower-case letter following a cap.

And letterfit is my problem with Stemple Garamond, at least, when used for text. I've never been able to get the letters to fit well. I even threw out all the sidebearings & started over. Still couldn't get it to work. Of course, that could be just my failing; somebody else might be able to get it right. But if so, I haven't seen it.

Looking at my copy of Adobe Garamond, the above graphic doesn't reflect the metrics in the font. In particular the tight Ad and Ga are not native to the font.

General look and feel is modern and clean.

Then why Garamond? It's a dirty old-style. (Dirty in the sense that all the revivals simulate the trace of the letterpress process, in particular ink gain, in some way.)

Garamond has been much used to the point of becoming generic. So you could pair any sans serif with it; but perhaps another much-used face would be a suitable companion. Any bundled sans would do--Futura, Helvetica, Gill, Myriad, etc.