Sims
The ex-bmi sim at Heathrow is now part of the Gecat setup, however they will not let you use any of their their sims if you are practising for one of their customer airlines, which is fair enough.
The Oxford sim is not the real thing, so that leaves Alteon at Luton or the Fungus sim in Dublin.
There is I believe a 200 sim in Yorkshire which is not too far off the 300 as assessments are all raw data anyway.