"Synch field" RFC

I'm beginning to work on a CCK field for this here module starting today. Basically, my intention is to create 2 modules:

Entity field

* Store an ListID value in CCK, as it relates to Quickbooks' internal identifier
* Implement some work in QBWC to effect a merge of Drupal/QB: Based on the value of the ID field, populate other fields in the node with QB values.

I did something quite similar on the Project Vote Smart module, where the remote data translated to a series of tokens, which were in turn used to populate other CCK values on a node.

Thus, you'd create a node that gets mapped to a given ListID in Quickbooks. When QBWC connects, the related entity's values ( e.g. FirstName, LastName ) are mapped to Drupal field values ( e.g. Text: field_first_name, Text: field_last_name )

I understand this is a little brittle and rife with merge issues. However, I think I can make a limited-use-case version stand up for now.

List Item field

* Create a field which would contain a select list of values ( just like the CCK text field does now )
* Periodically update available selections via QBWC, so that your UI's name/value pairs map to Quickbooks' ListIDs ( think CustomerTypeRef, PreferredPaymentMethodRef, etc. )

I'm tempted to simply use text.module and add QBWC behavior that populates the values. But I probably won't for integrity reasons.

I'm looking to start on this now/today. I'm interested in ideas, use cases and input on how the QB module is being used and how it can/should function in this way.