I need a Tachometer

So, I'm trying to find a Tach for my 5 hp Briggs and don't seem to be having any luck. Can anyone point me in the right direction or give me some advise as to what they've done to solve this problem?
The power of search engines/ebay. Go to ebay and type in "small engine tachometer"
I tried the obvious ones like google and what not but, it's hard to find anything that'll work with a Magneto Ignition system. Like the one that's on my Briggs....I'm currently talking to Sunpro to see what they can come up with. I'm hoping they'll have an analog tach that I can use.....