Quote Originally Posted by Mainecoonmaniac View Post
A common fallacy is the more the better. I've fallen into the trap many times. I have a set of Mole Richardson Mini Moles which are 200 watts. They're fresnel lights and they're my favorites. I shoot mainly tabletop and portraits and 200 watts is more than enough for me. On a recent assignment, I had to use some scrims to dim them over a stop to balance them with the ambient lighting. I don't know what you shoot nor what your approach is, but use your lights a bit and come to your conclusion through experience. If your lights permit, you might be able to up the wattage just by changing the bulb. But read the instructions first.
The first half of this is true, but you cannot increase a flash's power by changing the bulb. It's the quantity of capacitors built in that defines the energy storage.

But certainly 2 of 200Ws is enough to get started, more than enough for 35mm and OK for many purposes with medium format. It's only LF where it would struggle.

I will disagree with MattKing and strongly advocate the use of a DSLR for metering, if you have one already. If you set it up correctly (absolutely no dynamic-range-adjusted modes, M exposure), it can give a very accurate indication of exposure, especially if you look carefully at the histogram. The greatest value though is in visualising how the light falls on your subject, which can be a bit difficult initially with flashes. A flash meter is also highly valuable but they're not cheap.