Which wireless adapters can I use with a DIR-655?

First of all, I haven't posted on this forum for over 2 years. It's good to be back. I have a question and I hope you guys understand me since I have almost no knowledge in networking. I have a D-Link router that supports all of the wireless modes like N, b/g. There's 2 desktops hooked up to it along with a VAIO using the wireless and my Wii. It's set on Mixed Mode right now. I might move downstairs and I don't want to make holes in the wall for a cable from the router to the desktop. Can I use any wireless adapter from D-Link or does it have to be one that's for wireless N? What are the pros and cons of getting the cheaper D-Link adapters?

Yeah, that's what I thought so. Thanks a lot. Yeah, I'm really surprised how slow the internet in America is. Compared to where I'm from (Bulgaria), it's almost twice as slow for the same price. To make it worse, Bulgaria isn't even a "fully developed" country like Germany or Japan. It's kind of sad to see America be this behind on important technology.