Explain Resource Types for OSP

Assembly item uses primary UOM=KG but is always ordered in increments of 200 which represent a fully packaged assembly.

Need to setup OSP item and resource for the packaging operation where the purchase req = 1 for each assembly increment of 200. What is best OSP item UOM and where would I setup a usage qty (.005) that would calculate to 1 for each 200 assemblies?

Also, setting up Resource for OSP how do resource types 'Amount' and 'Miscellaneous' function?