I’ve had a Rostra electronic cruise control in my 1960 for about 10 years or so. It’s very simple to install compared to the older style with the vacuum canister and mechanical switches and ball chain for the brake and clutch pedal. I mounted the main control unit inside the firewall next to the heater, so the only visible item in the engine compartment is the cable going to the carburetor.
I bought mine from Flaming River, being the only place I could find one at the time. Summit also sells these now, although it appears you have to buy the switch separately. There are several style switches to choose from, either a replacement arm that attaches inside the column (which I have), or a universal model where you cut off the knob and attach it to the existing shaft. Ron Francis has a link showing the various style switches available, but the price is twice as much as Summit. They have all the styles on their site, but you have to search under "cruise control". If I paste the search link it doesn't show anything.
http://www.rostra.com/cruise-control.htm
http://www.flamingriver.com/index.cf...rod/prd293.htm
http://www.summitracing.com/parts/RP...1223/?rtype=10
http://www.summitracing.com/parts/RP...3032/?rtype=10
http://www.ronfrancis.com/prodinfo.asp?number=CC%2D25