Regional are about to start a course of 6 f/o's. I am not sure if they have any need for more F/o's at the moment.
Re experience: You sound like you have a fair chance. Generally they are not so keen on minimum hours guys. Prefer 500-700 hrs instructing, or similar.
Basing is never going to be set in stone. If you ever get offered a job, you are unlikely to find out your base until just before/during Line Training. LHR is not a base, but a secondment done on volunteers/seniority. MME just announced as new base starting 26 Oct 2008.
Roster is pretty stable though. 8-9 days off per month. Around 2-5 days stby per month (Must be within 1 hr of base airport). Good routes within the UK and to Northern Europe/Scandinavia.
Very much a good airline to cut your teeth on. Time will tell if it can be a career airline though with the potential Lufty/Virgin/something else merger.
Good luck.
SSS