Partial Landed Cost and set up by Supplier

Is there any way to do partial landed costing during a receipt?

For example, we have 10 cost level in a landed cost rule. For 6 cost levels, we can define a percentage as we know the cost in prior. For the rest of 4 levels, we will get the cost after few days.

As the first 6 levels are majors costs, we don't want to wait for the last 4 cost levels.

Also is there any way to set up landed cost by supplier ? We can define it by Item and B/P combination. But how about Item and Supplier combination ?