If the office is in Chancery Lane most commutes will be out of Liverpool Street into places like Essex - don't be put off by media "images" of "Essex girls" and "Essex lads" - depending on where you choose, Essex has some of the most elegant countryside and pleasant suburbs, as well as well rated schools eg Chelmsford and Colchester (secondary schools, ie high schools). There's no different in the accent between London and other Home Counties - it really depends on what kind of school and area you live in. I haven't calculated the commute from the areas, it obviously depends on how far the office is from Liverpool Street (might sometimes be faster to walk from the train station rather than going to Chancery Lane tube, speaking as a former resident of the area.) www.nationalrail.co.uk/ will give you train times and journeyplanner.tfl.gov.uk/user/XSLT_TRIP_REQUEST2?language=en will give you some idea of tube routes and times. I would not even contemplate using Waterloo, Paddington or Victoria for Chancery Lane (you'll spend half the morning getting across central London, so to speak) but London Bridge is plausible if you are not happy with Essex or other routes out of Liverpool St. So I would forget Harrow, Acton, Brentford, Berkshire, Oxford, Hillingdon, Buckinghamshire, Middlesex. You're essentially looking at the eastern suburbs and home counties, because of where Chancery Lane is. Also Liverpool St is a very easy station to get in and out of with lots of frequent trains- London Bridge is huge to get across. But check the route planners. London Bridge serves East Surrey, Sussex and Kent which themselves have lovely schools and places to live. Charing Cross is a too far IMHO to get across to Chancery Lane. Cannon Street is good but not many lines, and also consider whether you might need to go into work off peak or at weekends, when Cannon Street has limited or no service (depending on when that is).
If you have a very lively dog who wants space (not to mention your children and yourselves), then the best option is a house in the home counties commuting into a station near work but avoiding the tube, rather than a small house or a flat in a London postcode. Parking in the home counties is often so much easier (and cheaper!!) - London virtually has no free parking left (in practical terms - I don't mean at 2am on a weeknight!), and in London suburbs, parking a car can be a nightmare when you get home sometimes. A short distance on the tube (=London subway) also works out more pricey than a medium distance on the train in terms of the cost of your husband's daily commute. Timewise the train is often faster than the tube because the tube stops at so many stations.