Unit of Measure conversion issue in SAP

The Issue
Currently,
Material master is setup as a BUOM in Lbs.
Purchase order is created using BUOM
Vendor invoice is billed in Kg's.
Is it possible to enter a purchase order in a different unit of measure from the BUOM.
This change is required because, we buy stuff in lbs and pay to the customer in Kgs, so wanted to have the UOM in Kgs from the purchase order to the end of the transaction.

The Solution

Let me try to summarize and add a little information about UOms for you.

1) UOm for a particular material should be maintained by your own Stock keeping Unit, and not based on what vendor's or customer's own UOm.
2) In Material Master, you can set Order Unit. This means that for every vendor, the Order unit is XX. Alternatively, you can leave this field empty and set the Order unit in Info Record. I'm saying this because, maybe, the Order unit is only relevant for a particular vendor and not others.
3) In Material Master, you can also find Unit of Issue. Meaning conversion for Production Purposes.
4) And lastly, UOm for Sales. This can be done from Alternative unit of measure in Material Master.

So to sum up, you can maintain your Material A in EA (Each), Order it from Vendor XYZ in CAR (Cartons), Issue it in BOX (Boxes), and sell it in DZ (Dozen). Just an Example....

Source: http://forums.sdn.sap.com/thread.jspa?threadID=1661793&messageID=8994862#8994862