homemade bongs with slides are nearly non-existant.... usually a homemade bong just has a carb... but if you are to make your own, just use your imagination dude, go browsing through a hardware store and assemble it in your head, start by finding a body, then from there go to the bowl setup, you can try to find a slide mechanism, but i doubt you'll find one...

anyway you go about it, just use your imagination....

there are also glass bongs that aren't custom made, can't remember what they're called, but mine cost me around 50 dollars and it's atleast 12 inches tall... they just don't have as much personality to them as other glass bongs.