Home Network :: Having A Second Access Point With A Different SSID?

i live in a two story townhouse. under the stairs, there is a small closet where the modem and router are. there are also three ethernet ports, one that leads to each of the bedrooms. However, the only one that is being used is my room (my roommates dont need ethernet) so what i decided to do was run the ethernet port from the modem directly to my room and then connect the router to it using the ethernet port in my room. (my room is upstairs)

Now, this setup works great for me. I can connect my HD to the Airport and my printer via ethernet and my desktop as well. BUT ever since i moved the router upstairs to my room, the internet has been EXTREMELY slow downstairs

so this is what i was thinking, I want to get another wireless router and put it downstairs where the modem is, and use my airport Extreme as the "second" router. But, i want to use a different SSID for my airport extreme. is this possible?

I was thinking to connect the new router downstairs like normal, and disable the DHCP server on the airport extreme and change the IP address to make sure it isnt the same as the new router, then connect the new router to one of the three ethernet ports on my airport extreme.

Is that the correct way to set it up? and if i do that, would i be able to connect all my devices without a problem? (in addition to the devices mentioned earlier, i also have a second printer, a PS3, a home entertainment system, and sometimes my laptop, all connected to the airport via an ethernet switch) and lastly, will I be able to access the internet without a problem? will this slow down the internet that i get?

the reason i want to do this is because 1) I dont want any of my roommates or their guests to access my hard drive (i know, i can put a password on it. but still) and 2) if my printers are on the same network as their computers, they like to "accidentally" wirelessly print to my printers. I want to avoid that because they print. alot.