Thanks HoppyUK,
I was wondering which way around would be best but I thought the Lencartas woudl be best suited to lighting the background (but I know nothing)
Is this due to colour temp or some other reason that I am yet to understand ;-)
Cheers
Lee
I use hot-shoe guns for the white background because I can get f/8 at quarter power over 6ft-ish wide no probs, so fast recyling, and one either side gives even light when they're set up properly. Plus I don't need modelling lights there. Basically the advantages of studio flash are not necessary, so why buy two more of those when I've already got a couple of hot-shoe guns I can use.
Don't worry about colour temperature differences, really not a problem. Experiment with your two Nikon guns, get the power exactly balanced, the zoom setting, distance, angle (45 degs), note the settings and it'll be dead easy to replicate that any time pretty much by eye. When you're testing, do one light at a time and use blinkies (highlight over exposure warning) to moderate and balance the exposure.
I don't shoot portraits at high f/numbers, f/5.6 usually, the background doesn't have to be any higher than f/5.6 plus a half stop. If I was shooting bigger groups over a wide background and needing a higher f/number for depth of field, then hot-shoe guns would quickly run short of power and I'd be forced to crank them right up. Not good, slow recycling is death to a good portrait session, and then you start having to push the ISO or get a booster battery pack etc and then you'll be better off with studio lights. But if you can keep within the limitations of hot-shoe guns, they work great.
For the front key lights, that's where you want the control, nice reflectors/ modifiers, modelling light etc. You'll find they'll probably be turned down pretty low for f/5.6.
Anyway, the answer to your question is that studio lights are always better if you have mains power. Given the above, you may be able to get a way with hot-shoe guns as I do for the background, if you remember the limitations. On the other hand, a 3-head Lencarta kit is not a huge amount of money and then you have the best of all options. You can still work in the hot-shoe guns for an effect light or hair light or something, as and when.