Hi Rich,
As explained yesterday the 10w is more than sufficient for most of the diving you'll be doing over the next year or two. In fact one of my buddies has a 10w and the beam is much tighter than mine. An alternative is one of the Greenforces
LUMB BROS Umbilical Torches which you should be able to pick up second hand within your budget.
You might be lucky enough to pick up a second hand Salvo or Halcyon but they don't come around in your budget too often and when they do they're snapped up in no time.
I don't have much experience with the Greenforce torches but the ones I've seen don't focus too tightly so the lighting is more spread or diffused (if that's the right word) and so you don't get the penetration. You also find in high lighting conditions that signalling is not so easy. (Some might say you wouldn't need a torch in high lighting conditions but if you have to follow in single file then having a torch with sufficient penetration makes communicating with your buddy in front/behind much simpler).
With a second hand Halcyon or Salvo you might want to upgrade bits of it (one thing I'd recommend is the sealed switch unit as this prevents water ingress into the battery compartment). The older Halcyon's did appear to have bulb fragility problems. I don't know if that's resolved now but I'm led to believe it is. Some of the Salvos had a clip pin rusting problem. I think it was a batch issue but I think Adrian Kelland knows most about it (besides Phill obviously).
Brightstar do some torches but I don't think they are umbilical so probably not what you're looking for.
Personally I'd buy something that you can grow with (such as the Halcyon or Salvo) but to be honest for the diving you will be doing for much of this year your torch is fine or buy another Lenser if you prefer. That way you can save a bit of cash and get what you really want later when the dust settles over the emergence of the Frog wing
