Hi bloodtrakker,
If you go to the following link, you'll see what the different packages contain. Simply click on the package tab (see the image below).
http://www.pgmusic.com/bbwin.packages.htmAfter selecting the package tab, there are hyperlinks that will take you to a complete summary of what is sold with each version.
For example, with the MegaPak, if you click on the link I've highlighted below, you'll be taken to a list of what Realtracks are included.
The string quartets are not listed.
When I took a look at the UltraPlusPak, and clicked on the highlighted link, the string quartets did appear in the list.
Under the UltraPlusPak, I also found that the 49-Pak (marked with **), which is included with the UltraPlusPak, can be purchased separately and this seems to include some string quartets also.
I suggest that you get in touch with PG Music. Explain your situation and what you were after and then ask them about what is the most cost effective way of getting what you seek.
Hope this helps.
Regards,
Noel