Your best bet is probably to have a quick visit and put in a CV/chat to them all. Shouldn't take long as with the exception of Morrisons they are all down Main Street. A new one has just opened at our (south) end of Main Street so don't know how they are for staff. The others are all part of the same firm I think, maybe three? No idea of pharmacies outside of Main Street and Morries.
Your other option of course is St Bernards, the hospital. I assume they have a pharmacy department! Possibly Mount Alvernia too (old peoples home) or KGV (mental health). There is also a hospital at the military base at Devil's Tower.
That's all I can think of off the top of my head.
Are you planning to rent or buy?
Legit rentals start from around £600 (if you are lucky) a month, more likely £700, and properties to buy, ie a one bed flat, from £120 odd. Both Worlds (East side) and Ocean Heights come in cheaper, sometimes under £100K. Ocean Heights is convenient for town, BW isn't.