I've used a lot of Lowell kits through the years. I have a little one of my own now. I thought it was called the Jet Set kit, but I may be remembering wrong. It is a very small case w/2 V-lights and one Pro-light. The V-lights are 500 watts. (@110v) Totas use various bulbs ranging from 650 watts to 1000 watts. Omnis are 650w and are focusable. All the above can be used w/220v lights which I've done a lot in other countries. The Pro-light uses a small lamp, I think it's 250 watts. No 220 bulb available for it. It makes a really nice little hair light/back light for an interview. An Omni usually has to be flooded back and scrimmed in the same application. For travel, Lowell is tough to beat. I have a love/hate realtionship w/Lowell stuff. It's well designed and can fold up small for travel, but the instruments do tend to get beat up over time and require a good bit of maintenance to keep everything tightened up and functional. Also they are small relative to the heat build up they endure and the internal wiring often gets cooked. This can lead to shorts that can be very aggrivating in the middle of a pressured shoot. But they have every part available and they can be rebuilt forever. I've used some Arri kits - they are really fantastic. Big difference is that they, like many Mole instruments, are fresnels. ie: they have glass lenses which yield a much smoother and more controlable source. It does add considerable weight and bulk to the instruments which don't fold up small. Vaughn Broadcast Rentals here in Orlando (in the Champman Leonard building off OBT near the B-Line) rents the Arri kits. You might try renting one to see if you like it. I've used Mole stuff too and it's the standard of Hollywood, but so expensive. On the other end of the cost scale, you can get a lot of light cheap by using halogen work lights from Wallmart and diffusing by bouncing such as w/a silver umbrella or hanging diffusion material in front of them.
Portable softbox assemblies that fit on the front of lights such as those made by Chimera and others are fantastic. They turn a lensless spot into a very convenient and controlable softlight and fold up into about the size of a small lightstand or umbrella. I second the suggestion that one should almost always diffuse or bounce. Exception would be when using fresnel (glass lens) spots with their silky smooth beams.