The train down via Lewes is definitely a smoother option/there isnt any queuing but there are significantly less trains leaving LDN to play with.
As long as you are organised i would go via Lewes all day long.
1647 or 1719 to Ore or Eastbourne, they are platform 16-19 at Victoria, splits at Haywards Heath stops at Lewes
Takes just over an hour and will give you plenty of time,
May be full of Palace muppets though!
Are the Brighton to Falmer services really such a nightmare then? Am coming down early from London and planned to go to Brighton for a bit (I usually go via Lewes). What time does it start getting busy at Brighton station?