A friend has very kindly designed and produced (in HTML) our website - http://www.napa-technology.co.uk

I want to create a gadget to calculate pay back etc - just like this one:

https://spreadsheets.google.com/ccc?key=0Ak7w8e-WyzvkdEk0NklqdDltd3F0NGFkTER6eEJybGc&hl=en_GB

Just want to assess the feasibility as I'll be looking for someone to do this and want to know what i'm asking for!

Any comments on our new site are much appreciated - I like the design personally but think it could be modernised a bit in terms of layout, coding etc.