I used this tach:
2-1/16" Classic Diesel Tachometer 4K RPM with Lifetime Warranty | Custom Build Your Gauge
speedhut.com
Spendy, but quality. Theres probably something cheaper on amazon, but if I remember right I was having a hard time finding lower rpm tachs and all that china stuff has very mixed reviews. It wires into the key circuit for power, a light circuit for backlight, and a wire up to the W terminal on the alternator. It has a button to calibrate the rpm range. I just set it to the high/low in the specs of the tractor and haven't verified with a laser tach yet. Right now the gauge is stuck to the side of the dash in one of these mounts with some command strips.
Amazon.com
I used this hour meter:
I ran a new wire to the dash from the oil pressure switch for an oil pressure warning light, so I used that to trigger a 5 pin relay that runs the oil pressure light and the hour meter. Basically, if no oil pressure, light is on and hour meter off. If oil pressure, light is off hour meter on. I stuck the meter in one of the spare switch spots in the dash.