http://www.battlesbridge.com//events.php?article=78Bike show and autojumble at Southend on sea Sat 5th July.
I've never been to it, but it sounds like it may be a big event
DT-I don't know if you're familiar with the word "autojumble", they are events where dealers sell new and second hand parts and old bikes.
England Kev's photos here:
http://www.pbase.com/uk_kev/netley_marsh_2008 can give you an idea what a really good autojumble can offer. But that was a really big one.
However, what makes a good autojumble is whether or not it has the bits you need. I remember going to a tiny one in a scout hall, there were about 12 tables, blokes selling stuff to clear out their sheds. I went with 5 mates and we all left with something we were really pleased with. So you never can tell.
Regarding a place to stay, you'd probably best check out some "backpackers" forums for recommendations of hostels etc.
Cheers,
Iain