USB barcode scanners are rediculously easy to use. They work just like you typed the input into the keyboard. It should have very little effect on how you design your Access application. My experience was with USB wasp barcode scanners - they work great!
http://www.waspbarcode.com/
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Nathan...
Brandon,
I saw your post on control.com. I believe that FactorySQL and FactoryPMI from Inductive Automation are worth investigating. I think that solution easily meets your 8 requirements. I would recommend signing up for a web demo to see what it's all about and ask any questions.
As far as...