For Little Snitch, a good router with built in firewall in combination with the Windows firewall should suffice unless you are into serious hacking and whatnot. In which case, I would recommend a UNIX based OS, but that's just me
As far as Quicksilver goes, you may want to try SlickRun. I've never used it, but I hear it's the best windows alternative to Quicksilver. http://www.bayden.com/SlickRun/
Also, did I mention that all of these softwares are free?
Welcome to the world of not being a mac