I am a commuter (or used to be before the lockdown

) from Espom to the Bank-ish area (Houndsditch and then Ropemaker). Central Epsom is great because the station is IN the middle of town, pretty much bang on the High St (so many suburban towns have stations on the outskirts, in the middle of nowhere

) and has frequent direct services to Waterloo, Victoria, and LBG (e.g. Waterloo trains run every 15 mins during the rush hour). If your DH has to commute to Bank, looks like he'd have to go to Waterloo and then use the Drain. May sound daunting, but hear me out. Direct train to 'loo, then QUICK change to the Drain. The Drain is super busy during the rush hour BUT it's a "shuttle" line, which means that trains arrive EMPTY each time, so with a bit of patience and planning, one can always grab a seat, and, with a philosophical take on life, feel content about it (I know, it's prob stretching too far

). I'm not advocating it's ideal, but a SINGLE change between the train and tube takes away a lot of brain stress.
But, as PPs said, DO consider time to-from station. Before we moved, I was lucky to have a 10-minute walk from home to the station but my commute was still at least ~ 1hr 10min door-to-desk each way, which is considerably longer than your criteria. Also, we didn't live in the best part of town (it was by no means dangerous or bad, just not an eye candy) but there are plenty of prettier areas in Epsom that are within the same walking distance from the station, and, of course, there are lovely areas further away from the town centre, like elsewhere. Also, bear in mind that Epsom is outside a designated travel zone (you can use an Oyster card but it's just for convenience, there are no savings), so train fares are relatively high.
But all that said, for £800K you can bag a brilliant family house, and on top of that there are very good schools in the area. Have a look at College Area as @Movinghouseatlast suggested, or towards the west of town near the Epsom Common, or towards south near Woodcote area.