Honestly, I really don’t like using umbrellas at all.
Typical lighting set-ups use a 3-point lighting technique: A Key light, fill light, and rim/hairlight. In addition, background lights are used.
The options you mentioned above would be a start, and very helpful in lighting, but you may want look for a kit with three lights.
For diffused lights, softboxes, though a little more expensive, have many more advantages INO over umbrellas.
If your purposes do not need professional studio lights, you can get away with pretty fair results using just hardware lights. There are many 500 halogen watt lights out there for cheap, as well as many other options. Some of them include stands as well, while others have clamps, which are really convenient.
