Studio light question

I'm looking to get some studio lights. I'm thinking about starting with umbrellas because they are so much cheaper than the soft-boxes, although I hear that the umbrellas ribs can be visible in the pictures. I'm thinking about the continuous lights set up. Again, because it's the least expansive option. But I want to know what wattage would be sufficient? I saw a two piece set with two 350 Watts bulbs. Would 700 watts be enough to shoot at f/16, 1/200 second?

Controlling light with an umbrella is like herding cats. They spill light everywhere. So many people start with umbrellas only to buy better equipment after suffering with lousy equipment; thereby spending more and producing poor photos until they realize the source of their inability to produce the lighting they pre-visualize. It's a tragedy I've seen repeated many times. I'm sure 700 watts will be sufficient to shoot at f16 and 1/200, but at some ridiculously high ISO.

I don't have a lot of room for a dedicated photo studio, so the convenience of being able to fold up an umbrella and stick it in the corner works better that a big soft box for me. You can see the ribs, but only on highly reflective subjects: