Hallo,
As Martin said - if you're here for 6 months, get yourself the tank &c. - perhaps £20 of your money and you'll be doing a better job than any lab.
I've never sent B&W film to a lab, but looking around expect to pay around £15/roll - perhaps with a contact sheet... Not soon before you realise doing it yourself is going to be cheaper, eh?
If you do still want to send it to a lab, let me know.