What VPS requirements for trading platforms ?

Which one of the following plans do I need to run trading platforms like Interactivebrokers, MBtrading and webplatforms on a VPS ?

http://www.xtrahost.co.uk/virtualisation/windowsvps.html

 

Dual Core 4GB RAM should work well. A VPS provider in NY may be better suited for accessing US equity markets.

 

For a webplatform the first plan with 512 MB should suffice ?

 

512MB is "ok" if you are only auto trading and not trading using a ton of charts and indicators, but seeing the price difference, I would shoot for 1GB.