If you're running one cable, I'd always run 2 if possible.
For "splitter" you are actually after a network switch. These are usually 5, 8 or 16 port - so for 4 devices, you need a 5 port ("incoming" wire from router uses one), more than 4, you probably need a life, geek boy
. These come as 100Mb and gigabit (at prices you're looking at). Personally I'd go gigabit, so at least the link between SH2 and switch is gigabit, and gigabit is almost as cheap at these small scale implementations.
If you want to test/play first, lets arrange a curry, and we'll pop over early, throw a cable down the stairs, bung on a gigabit switch, and run some tests
. I can bring the Mains Adapters over as well for testing. At least you will know if/what works for you before spending.
Obviously, the virgin line is the limit, and due to shared nature of Virgin lines, I'd expect slowdown at peak times (as opposed to ADSL/FTTC type products that only slow down due to ISP capacity (except in now rare cases of exchange congestion)). Other circumstance dictate your need to use virgin, so that's out of our hands.
H was just saying we have'nt had a furry for a while. There's a new place opened up near the Chinese in the precinct. It's always busy....? But then so is everyone here 
Or there's the usual places 
We can do chinky (had one last night

), we can do curry (had one tonight

).
