Route Advice - SE London to Guildford

the route that you are talking about is probably the best, but it is a gruelling route to ride, might want to try going through epsom, leatherhead etc....

yeah the A232-A24-A246 wouldn't be that bad... I've done the route on the weekend from Addiscombe (not far from you) down to dorking then back past redhill and up biggin hill.

so I don't know the route on the 246 though