Best practice for set up of R12 Procurement document styles

Hi,  We are going to establish Services Procurement and complex payments. 

We have some discussion on how many new document styles to create in addition to the seeded document style.

 Option 1:

Purchase Order (doc style) with following purchase bases:

• Fixed Price Service
• Temporary Labour
• Goods

or option 2:

Purchase Order (doc style) with following purchase bases:

• Goods

Service Order (doc style) with following purchase bases:

• Fixed Price Service
• Temporary Labour

A typical example of a purchase can be:

Purchase of Hardware (goods), with 5 year Service Agreement (Fixed Price Service PO with Rate Based Payment Plan).

Does anyone have experience to share on this issue?