I think for a portable setup, speedlights, on stands with umbrellas is perfectly acceptable, as the whole setup is lighter, and a speedlight is going to be more versatile than a continues or studio strobe, given the fact it's self contained unit, you can use it on a lightstand or on a mini tripod / gorillapod to get it in different positions, as well as being quicker to setup.
If you were in a studio, then it's a different situation, but with a studio, the gear will be setup before the client gets there, so all they will see is light stands and umbrellas / softboxes. the only think a speedlight could be lacking is the power for the bigger soft boxes / diffusers.
I can see where you're coming from, in terms of appearance, but do you think that someone being photographed is going to know the difference between a lencarta setup and jessops own brand speedlights working off a trigger?
That said if I had £1000 spare, I'd probably be looking at a proper studio light setup, although I'd probably go for a macro lens and wideangle lens instead.