Magic Tricks

Well, you've gotten the main part correct...the art is in the presentation!
Stipulating that we have no idea what is in your 'standard birthday show', and not knowing your budget, it's somewhat of a 'shot in the dark' to recommend tricks for you.
That disclaimer aside, PM doesn't really have a section/tab for "Kids Shows" specifically. I'm not sure why they don't...this has come up before. They have a 'tab' for everything else.
Nonetheless, perusing everything available that may fit your genre could be time consuming.
Thus, although PM is my favorite/recommended vendor, check out this link for product ideas...at least they've put some effort into determining a 'kids magic' category.
http://www.hocus-pocus.com/magicshop/
Hope that you get this soon...it would be understandable if my post were deleted.
Good luck.