electronic speedometer turbo 350

I have not yet decided what to run for gauges in the roadster pickup, but found something out yesterday. You can't fill a turbo 350 with new fluid when the speedometer end is not installed in the tranny. I found this out the hard way, by pouring a gallon of tranny fluid in the filler tube, and having it immediately run out onto the garage floor. (stupid old Fart, I should've known that) . Anyway, that got me thinking, what am I going to do for a speedometer?---the last 2 rods I built, I used mix and match junkyard speedometer parts. They worked, after a fashion, but I never really knew how fast I was actually going. This time around, I'm thinking, gee, maybe one a those high tech electronic speedometers, that I can set for kilometers per hour, (yeah, I'm up here in Canada where nobody really knows how fast they're going now that we've gotten rid of miles). Does anyone know who sells them, what they cost, and do they have an end that plugs into a turbo 350 (1985 version in my case)? Thanks for your help. By the way, since I haven't purchased any gauges yet, (don't even have a dash yet), is there a stock electronic speedometer setup, readily adaptable for street rod use, that anybody knows of, from something I might find at a wreckers?