Hi Damian & welcome to the forum.
DBS seems to be coming back into popularity with drivers. When I considered moving across to them a while back they were called EWS (English Welsh & Scottish) and their drivers were leaving in droves because of awful T&Cs and bullish management .
However in the last few years they appear to have turned a corner. Several of my friends have gone there recently as qualified drivers and are very happy.
In any case I think the best advice I hear regularly is that since competition for Trainee Driver's jobs is so intense, you really need to go with
any TOC/FOC that will have you. Work hard (and everybody has to) and you will get your key. Then do a couple of years service to get good experience - and by then you'll probably know what sort of trains you REALLY want to drive.
As Mike 2E0BLL says, railchat.co.uk is the place to talk to railstaff.
But don't give up on us either - we're nice people too.
Best wishes, BW