craftgrrl | embroidering and hoodies

I have a hoodie I stenciled on a while ago
and started thinking that I want to embroider something similar to this on it
(probably not exactly the same and with color instead of grayscale)

I was wondering how I should do this so it stays through being worn a lot and washed sometimes...

would I be able to just do it directly on the hoodie?
would I need to put a piece of fabric on the inside to better hold the thread?
do I just need to give in and do it on fabric to make a patch and then sew that on my hoodie (not so enthused about that option, though)?

thanks
-kate