taimatsu no monogatari

So, tomorrow (Friday) is my littlest brother's 18th birthday. I have to be in Wimbledon, sitting at a restaurant table, at 8pm. I'm going to aim to be at my dad's house (Raynes Park) for 6pm, just in case. Where should I be going for updates on transport and realistic advice on the best way to get into town from Reading? At the moment I'm considering (if it's running) the slow train to Waterloo - it'll take over an hour, but I can get off at Clapham Junction and thus go overground all the way. Getting a fast train to Paddington would probably be silly. Advice welcome!

Edited to add: If I go via Clapham and Wimbledon it's South West Trains all the way, and they say they're running a normal service tomorrow. If I have trouble I could, assuming I've left enough time, get someone to collect me by car from Clapham or nearby stations. So, given I'm familiar with the route, I think I'll go for that, unless I work out tomorrow that it will be particularly problematic. Robert will be driving back with me afterwards, as the family have a houseful of relations and friends from overseas, so the return journey is fixed. Thanks for the help and ideas :)