Second the Kill-a-Watt.
It will just plug in to any outlet and give you volt and freq info. You can also plug an apliance or power cord into it and it will tell you the electrical load being drawn thru it in amps or watts up to it's 18A/2KW maximum. It will also give you the power factor for inductive loads. It will totalize an electrical load, so you can plug in the freezer for a month and see exactly how much power it is consuming short and long term in KW hours. Pretty handy for doing an electrical load study of your plug in appliances and seeing how large a generator you actually need. The older model will unfortunatly loose all it's stored information when it is unplugged but mine is handy. I guess they have a newer model out now that has a memory battery in it so it retains the recorded data when it looses power. I assembled a slow speed diesel generator this past summer and that is my only generator instrunment. I use it to set and monitor the RPM/frequency. Harbor freight recently started selling them in their stores, I am not sure if they are on their website or not.
As for an hour meter, you can get one from surplus center for around $24. You will need a small 12VDC or larger plug in power supply to power it. They run on 10-80V and consume about 6 watts if I recall the label on the one I just bought. The battery operated/inductive pickup models used on many lawn and garden tractors are pretty expensive, but would make a more compact installation on the pictured generator.