Index/Match for a lookup involving 2 criteria

I have a workbook attached for my problem.

I have 2 criteria lookup using an index and match but it doesn't appear to be working quite as I would like. The problem is rather than having my criteria being exactly equal, I need my second criteria to be greater than or equal to a number which has caused some bugs.

It's quite obvious what I'm after if you open up the workbook as I have stated my requirements and conditions. I have even got a section for you to try your own solution so I can compare against my own tries.

Thanks in advance if you have a go at solving this, it's much appreciated!

Oilman.