Handling Evals versus Orders

Has anyone setup a working model for handling sales evals?

My company sells hardware which we maintain in inventory and sell, performing fulfillment, shipping, etc. All inventory is in one location. Our sales teams routinely need to do sales evals where we must ship out equipment to prospects for 90 - 120 days and then get it back. Evals can not be placed back in product inventory as they are no longer "new" and instead we want to create a sales pool specific for performing evals. Briefly, here is what we are trying to accomplish:

1. We want to maintain a sales pool for shipping product to do sales evals but this should not be an asset account but rather an expense account (products are expensed out of inventory to the pool). However we want to maintain tracking ability of the product's serial numbers just as we do with product inventory.