Sal,
BGS mod 1 took me about 8 months (slowed right down for a bit after Sep 11 plus don't tend to do weekends), but work about 3 to 4 hours every week night, with the odd Friday taken over by Monsieur Stella.
Should be taking mod 2 exams in September so if all goes well, just over a year with working a full time job and doing the study pretty much full on most evenings.
It really is a case of putting your life on hold for a wee while and really making it the norm to come home from work, eat, then study.
I think Bristol state on average it can take as little as 6 months to complete (flogging it pretty much full time), to on average a year.
Your plan sounds ok, I would just echo some of the guys other comments, be prepared for it to go a bit longer than that, 7 months doesn't really leave you any slack, and there will be times when you don't get through as much as you initially schedule.
Good luck with it, enjoy !
