Hi Brad,
Based on the second paragraph, my suggestion is to use the entity Product and Product's Lines, moreover the concept of Product's sets, which is possible to define a set of products as na only "product" or "service".
Based on the first paragraph, I consider it's possible to customize the entity Quote to comply the needs and include the entities mentioned above.
Sorry for some misunderstanding.
Regards,
Thank you for using Microsoft Dynamics CRM Communities,
Gustavo Dobkowski Longo
Support Engineer
Microsoft Dynamics CRM