I think your best place would be Canary Wharf - that's where all the big business' have their offices, for example the HSBC tower. I thought the gherkin was around there too which is a really cool building but I can't see it on the photo:
http://www.tleo.co.uk/files/projects...%20wharf_0.jpg
Just generally along the banks of the Thames there are some pretty impressive skylines, with St Pauls, the Eye, Big Ben and Westminster
though, actually I've only been to London about twice so don't hold me to that!
Hmm, I don't know much about horses but I did a little research and found this rather useful looking website.
http://www.bhs.org.uk/Content/Inf-Di...7&title=Breeds
Basically if you click on any of the links it gives you a picture and information on each of the breeds which could be a good start point for you.