There is a whole lot of styles out there for the transgender community, the problem is where to look. If you are lucky enough to have average sized feet then you have a lot more choice the normal High Street store will cater for people up to about a size 10 although Saxone is known to go up to size 11.
On the other hand if you want something a little larger or sexier then you can always try Lisa's or Hayway's they are extremlly good value. You will find these and other useful links on my links page
You can normally order the same as a real girl sizewise so there should be no problems.
The one thing to remember is the heel size, if you want to go out walking around town then it is not very wise to have a 4-5 inch heel, you would be much better with a 2-3 inch. By all means have the higher ones for partying etc., but it will kill you feet to walk around town all day.