It’s called an RFP (Request For Proposal) where YOU lay out the features that you want in priority order, arranged with appropriate sub-categories, as meets your requirements.
Then each vendor (assuming that they want to play the game), replies to that IN THE SAME FORMAT, with whatever they’re offering.
Here’s a simple example:
Desktop Support/Management Package
1. Remote Control
1.1 IT must be able to view users desktop
1.2 IT must be able to take control of user’s desktop
1.3 IT must be able to prevent user interference
2. Patch Management
2.1 IT must be able to get a patch configuration on demand from any live desktop
2.2 IT must be able to push patches from a central point
3. Configuration Management
3.1 IT must be able to control configuration of applications (Browser, Email, Word Processing, etc.)
3.2 End user must only be able to change certain limited things (screen saver, background, etc.)
4.1 IT must be able to push new virus definitions
4.2 IT must get reports of all virus activity
4.3 Inbound email must go through local anti-virus proxy
4.4 Sent email must go through local anti-virus proxy
You get the idea. Then, each vendor must respond to each line item with a product/feature with a price next to it.
You can enrich the definitions by specifying Must have, Nice to have, or Optional (pick your definitions) with each one.
Hope that helps,