Trying to generate a prices list using index and match............just cant do it!

Hi thanks for looking an hopefully some answers!
I have a price table which consists of width X drop with the relevant prices in the grid. What I want to achieve is the user enters their width in the yellow cell and their drop in the blue cell. I would like a drop down box by the yellow and blue cells that gives the option of inches, mm, cm and mtrs (the price table is in mtrs) with the necessary conversions to arrive at the end price in the green cell
From there I would like the price to show in the green cell which is rounded up to the next size upwards if the size does not match the cell.
e.g if a width of 1.270 X drop of 1.270 the price would be £24.89
but if the width was 1.271 X drop of 1.271 the price would be £31.98.

I have been trying for some time with no joy and have come to a brick wall. I have cleaned the formulas from the work sheet to avoid confusion.

Any help would be greatly appreciated

Yes it is, however the problem has been solved and working !

The problem was solved by ACE a very knowledgeable person who kindly generated a very long formula for me that I would never been able to do myself. Many thank go to Ace from me.
For those interested the sheet can be seen working here:http://www.godivablinds.co.uk/prices.html
and the formula used was:
=IF(OR(B1/LOOKUP(C1,{"cm","Inches","m","mm"},{100,39.3701,1,1000})>MAX(Width),F1/LOOKUP(G1,{"cm","Inches","m","mm"},{100,39.3701,1,1000})>MAX(Drop)),"Too Big",INDEX(Price,IFERROR(MATCH(MAX(MIN(Drop),F1/LOOKUP(G1,{"cm","Inches","m","mm"},{100,39.3701,1,1000})),Drop,0),MATCH(MAX(MIN(Drop),F1/LOOKUP(G1,{"cm","Inches","m","mm"},{100,39.3701,1,1000})),Drop,1)+1),IFERROR(MATCH(MAX(MIN(Width),B1/LOOKUP(C1,{"cm","Inches","m","mm"},{100,39.3701,1,1000})),Width,0),MATCH(MAX(MIN(Width),B1/LOOKUP(C1,{"cm","Inches","m","mm"},{100,39.3701,1,1000})),Width,1)+1)))