Can you recommend some classical CD's for me?

This might be a good starting point. The author is a music professor at the University of Washington and has been a very patient classical music mentor to local audiophiles:

http://www.durand-tonearms.com/Support/Greatrecordings/Classical%20Music/classicalmusic.html

Steven Isserlis has a Saint-Saens disc on redbook that has the 2nd cello concerto and the 2nd cello sonata plus Joshua Bell on one piece. He also has a redbook CD called Cello World that does have some but not a lot of vocals.
If your are familiar with Rostopovich his version of Dvorak's cello concerto is my favorite.
While not positive I am fairly sure there should be an SACD of Jacqueline du Pre's version of Elgar's cello concerto.
For guitar check out Christopher Parkening,
Also Julian Bream and John Williams did a couple of albums together.
Would also recommend Laurindo Almeida, and Segovia. You can check them out on Arkivmusic.com and see what they did doing.
Hope this helps.
I know it only scratches the surface but one has to begin somewhere.

This excellent reference tool would be a good start: “The NPR guide to building a classical CD collection” by Ted Libbey

The MA recording of Bach Cello Suites by Martin Zeller is a great version and beautifully recorded.

http://www.marecordings.com/main/product_info.php?cPath=47&products_id=142

The two Haydn Cello Concertos, played by Truls Mork on Virgin, are an excellent and very well-recorded version.

http://www.amazon.com/Haydn-Cello-Concertos-Franz-Joseph/dp/B000025XWR/ref=sr_1_2?ie=UTF8&s=music&qid=1299638877&sr=1-2

I would choose these as sure things for a start to a great classical collection.

Glen, two of my favorte ensembles that match your description of sound are The English Concert and The Academy of Ancient Music. Mostly Baroque, these two groups are primarily strings, smaller than orchestras, few if any vocals (I certainly haven't heard all of their works), and I enjoy listening to both very much. Sample online somewhere and see if you like 'em.