Apologies for the very late reply...!
The company I work for has taken it on, so effectively I'm now running ES.
We've taken on the StenLight stock and from the customer's point of view it should be 'business as usual' and we've got a decent supply of batteries and spares (basically everything other than the lamps themselves - see below!).
The aim in taking it on is to develop ES with a wider range of products, which will be outdoor activity orientated and are generally things we already stock physically but don't sell on the web at the moment.
Stenlight upgrades: yes, we can offer these. We've currently got a lamp away in the States being upgraded / repaired, but the turn-around time is not great and we want to see how it goes before we offer these to a wider audience.
There should also be a new version of the lamp coming in about 2-3 months' time. This should be about double the lumens, in the same body. Although it can be driven to give a higher output, the prototype I've seen is to that spec and gets a bit too hot when run on 'Turbo' for any length of time.
I understand that there was some debate about building a larger body to aid heat dissipation, but the decision was made that the benefits in output were outweighed by the heavier head unit.
We're still kicking around the scope for an upgrade/exchange programme for the new spec lamp - it may be easier to do a 'new for old' price which should get turnaround within a few days rather than having to send lamps on an 8,000 mile journey. Drop me a line if you want details when we've got an answer.