The standard bulb used for contacting is a 7 1/2 watt round style. If you can find one nuArc made the CP25 point source contacting light that's quite nice: timer, adjustable brightness, VC filter holder on the lamp housing (though it wants 3" gels, not standard under-lens filters) - if you wait long enough you can usually find one for $25 or so.

For exposure control you can use an enlarger timer. Adams used a footswitch and metronome and he did a dance with his hands above the contact frame for dodging and burning.