I've got the yeast for a BOMM but not put it together yet as been fermenting other things first.
Here's two links for an ebay seller who stocks
Fermaid O and
Go-Ferm, seems to be the only option in the UK without bulk ordering several kilos of the stuff. For Fermaid K, I use Tronozymol which is DAP plus a bunch of micronutrients, started using it when my first batch of mead stalled out using standard nutrient (in hindsight it was probably because the old recipe had the must too acidic).
My recent batch of rapeseed honey mead with Lalvin 71B started at 1.128 and fermented down to 1.060 before sticking, after a couple of weeks of rousing it, warming it, adding more nutrient, adding another yeast (CBC-1) and stepping it back up I then left it for 2 weeks while offshore and came back to it finished at 1.022 which was around my original aim. CBC-1 can apparently go over 20% if you feed it slowly but seems to have stopped a bit over 14% for me which is what I wanted. Tastes ok, but will need a couple of months to mellow out after all the mishandling, rumour has it that mead is very resistant to oxidation, this batch will stress test that idea.
Will try a BOMM soon which will keep us in mead for a while, hope they taste better than my previous attempts or I'm just gonna give up on mead. :-(