I don't have experience with a PCI card for WiFi, but the USB adapters that you can get for ~$20 work great for my wife.
Best Buy is having a great sale on Logitech stuff right now, you can get a G400 mouse for $30 or a G500 for $40. I have the 400 and love it. As far as a keyboard goes, that's purely personal preference. Just find one you like and go with it. I'm using a cheap Acer keyboard right now and am having no problems.