Re. Commuting to LGW: as mantioned above there are some tours available, but they're generally quite popular in the RHS as guys try and max out their take-home pay. They're generally more popular for FO's than Captains, and you'll see more uncovered ones for the LHS. And who doesn't like an afternoon bike ride pub crawl in Jersey?
I guess you'd definitely need some sort of bolthole. Generally day trips, and you can expect to do one or two trips clearing after midnight each month in the summer. There will be times where it's 6 on, 1 off, 6 on, and no-one will be too far away from 100 hours in 28 days by the time it gets to August/September.