Hi SingleDad
I think being a single parent anywhere is doable (having a good network and income of course helps massively) - been 'doing' it myself for years :).
In Kingston the primaries have good after, pre and holiday clubs, however the Council provides little in the way of any sort of free or subsidised activities during school holidays or indeed at any time of the year.
There is Richmond and Bushy Park, as well as the riverside if your kids are outdoors types. There's also the Kingfisher Leisure Centre, Hawker Centre and New Malden Centre, depending on which part of the borough you are interested in.
Indoors there's the Rotunda - bowling, cinema, child friendly food, Kingston Museum and the Rose Theatre.
The best primary or secondary will depend on where you live in the borough, whether for example you want your child to attend a mixed school or single sex, church or not, grammar or not. If you are looking at the independent sector there are a number of schools including Kingston Grammar and Surbiton High.
If you need more information, please feel free to ask.