Opps... that was 40 bucks shipped....   Have you looked on craigslist?  I still think finding an old cheap home one might be a good start (backboard/rim/balls), then building your own.   
As for designs.  I bet you could copy the basics from images of the others, or just go into an arcade/chuck-e-cheese.  I still see those everywhere.  
btw, happcontrols.com have the balls, the nets, but not the rims for the smaller size.  I think this might be the trouble you'll find.  And those rims might not be easy to just build. 
Just sort of started my research, I haven't even moved in to my new home yet (and my wife is already a little pissed that I just bought a full skeeball machine. 

) But thanks for the tips on those rubber balls Happcontrols sells ... I was just going to buy JR. actual basketballs, but these might be more "bouncy" like the way I remember it.
As for the rims, I'm pretty sure the newer versions use a traditional sized rim anyway, (NBA Hoops does), I'm not entirely sure what size the others have, but I've put in a "parts" request directly to skeeball for a quote. I don't know if it will be something I want to do just yet though ... still got a lot of research to pull off.
(Plus the wife is already demanding I buy her a massage chair ... since I bought the skeeball ...  wives 

)