you can't improve the thing significantly anyway plus they are 5 bucks.

Plus if you are just going to copy someones your not making crap, you are copying it.  You should know, and have design and board level experience and anyone that has that knows better than to make another 3-5 dollar product that's not tested and has to go through all these approvals to even be able to be sold. 

Long story short if you really want to do it:
buy one and trace it.  They are 2 layer maybe 4 max.