Desk Pilot,
To add to Exengs comments, I am a 6 year First Officer with BA and whilst flying on the 757/767 I now take home around £3300 but that includes meal allowances. I tend to spend around £300 per month when away from base so I suppose you could say my take home pay is £3000. Bad months £2900 good months (When I get Overtime) £4000.
Your best bet is BA, because you have what we call roster stability which means,
a) When you get a day off you wanted it will remain just that - a DAY OFF, not contactable or Standby or the many other strange things that the 'opposition' call it.
b) You can get work according to your lifestyle needs. So with a young family you can be at home more, whereas if you want longer periods away from home due to the fact that you live a long way from LHR, then this can be catered for.
c) Where else can you choose between a A319 and a B747-400?