Not sure what you mean by esop, not a term I've heard in the UK.
Probably expect to earn around 22-24k dependant on experience + allowances for lunch,van cleaning etc.(van + Uniform supplied) I'm ex-barlow myself and led to believe pay will be reviewed when aligning terms and conditions with Briggs.
If the depot you are visiting is the head office @cannock I'd give yourself 1.5 - 2 hours.
Unfortunately I'm a few hours from their or would have met for a beer, by march we'd be more settled in and could tell you more.
Maybe someone else on here maybe nearer and take you up on that offer.
Hope all goes well