ditch tech formula would probably be your best bet for where and what your skating i think they are more forgiving....... you should find some smooth concrete though, especially when your a beginner it will make learing tricks that much easier, and save yourself some frustration. wheel height is a matter of prefrence. but if your doing street tricks "exclusively" the smaller the wheel the lighter, and easier it is to do flip tricks.

yea i think a soft wheel would be the best way to go