Unified Quoting Solution for Repair, Field Service and Spares

We have the requirement to give one quote that has
1) Repair components
2) FS labor charges
3) Spares that are sold as part of repair/FS

We cannot create 3 documents for this as the customer needs to have one quote for all these 3:
1) Repair estimate
2) FS estimate charges
3) Quote in OM (or Quoting module)

The key requirements for quoting are:
1) Ability to easily convert the quote to order (the actual service charge line does not store the reference to the estimate charge line - so we loose the ability to see how many estimate lines have been successfully converted to order)
2) Ability to maintain the versions of quote when there are any changes (there is no audit/version history in service charges)