Hi!
Hmmm...That's interesting. Some people put beige and taupe in the same color category and I myself don't see much difference but it all depends. I guess it varies from person to person as to whether the two are similar in color or completely different.
Well, I have a link here to the actual taupe shoes that I bought, they are 4 inches though so I'm not sure if you'll feel comfortable in those but the site is Shoebuy.com. Not sure if they deliver outside the US but it couldn't hurt to look around their site if they do...they've got some pretty decent prices and nice shoes:
http://www.shoebuy.com/touch-ups-genesis/233406/499857
As far as the whole heel thing, what height do you feel most comfortable walking in or at least semi comfortable? I don't know if you have a Payless Shoe Store in the UK or an equivalent of it but maybe try finding taupe heels in that type of store that sells the shoes for much less and experiment. If you can at least find a decent cheaper pair of heels, maybe 2-3 inches, those can be your practice pair of heels that you don't have to worry about messing up. You can practice walking in those each day until you feel more confident in them and can perhaps move up to 4 inches and/or buy the actual taupe heels you want (if you can manage to find them!).