Just bought new time capsule- need help setting up WiFi network with another router

Question

Here ismy situation.
I had a wireless network setup up at home using a Belkin wifi router.
I have 2 macBooks (1 pro, 1 air) and 2 iphones that connect wirelessly and a desktop PC that is hard wired to the ethernet port.  In addition, I have a Verizon wireless network extender plugged in by ethernet.  All of the hard-wired gear is in our 3rd floor attic office (and the wireless signal was strong throughout the house).
The Belkin wifi router was plugged into a wall ethernet jack that is in turn wired into a Linksys router in the basement (along with multiple other ethernet ports througout the house) and is hardwired to the Cable modem next to it.  All of the hard-wired ethernet stuff (including the router in the basement) was there when we bought the house, and I have no clue in the tangle of wires how to sort them out (but don't really think I need to)
I just purchased a TimeCapsule to do wireless backups of my 2 macbooks, and tried to set it up alongside the existing wireless modem.
Needless to say, this did not work well. I called  AppleCare, and was told that the TimeCapsule needs to be the "1st" wireless adapter, so I went into the basement, and connected the time capsule directly to the cable modem, and then out to the basement router.  The Belkin router still needs to be in the attic to supply the PC and the Verizon adapter (so it is near a window for GPS signal). 
If I try to name the WiFi network the same SSID on both the TC and the belkin router (to have dual signal strenth coverage) the whole thing gets messed up and the TC cannot be "found" by the aiprort Utility software.
What I have done now is that I have 2 side-by-side wireless networks with 2 unique names (actually 3, because I enabled the 5Ghz signal on the TC), but our wireless devices do not "switch" automatically from one SSID  to another stronger signal SSID as we move through the house
Here's the question: How do I name them the same so that the devices will switch effortlessly to the stongest signal?  I understand it involves switching the "channels" but don't know how to do it right now.  Currently, everything works, so I don't want to mess it up tinkering.  Another caveat- there are several other wireless networks from neighbors houses that I can "see".  I jsut downloaded a program called iStumbler that shows the channels, but not sure what to do with that info.
Any advice would be appreciated.

Answer 1

Here's the question: How do I name them the same so that the devices will switch effortlessly to the stongest signal?  I understand it involves switching the "channels" but don't know how to do it right now.  Currently, everything works, so I don't want to mess it up tinkering.  Another caveat- there are several other wireless networks from neighbors houses that I can "see".  I jsut downloaded a program called iStumbler that shows the channels, but not sure what to do with that info.
Any advice would be appreciated.
OK.. sounds like a mess.. or at least messy and the previous people should have left a log book with all the IP address info in it.. you have far too many routers.. but from here it is impossible to tell how they are configured. Most are probably just setup as AP.
Naming rule for wireless.. Same SSID same security different channel.
SSID ie wireless name to work on the PC side should have no spaces and no special characters. TC name should also follow that rule. So the devices need to all set with fixed channels.
Don't worry too much about iStumbler and what is outside your house.. there isn't enough channels at 2.4ghz anyway. And you are going to need to use them all. There are only three non-overlapping channels. 1, 6, 11 so set each device to one of those channels. The TC should be as close as you can to where you normally use the MacBooks.. and turn on the 5ghz. You will have to leave it to automatic name so the Macbook can also roam across from 2.4 to 5ghz. But if you care to use a different name and force it onto 5ghz the speed is much better as long as you are in the same room.
Roaming is great in theory.. often in practice it just doesn't work.. you need to step in and turn off wireless and then turn it back on.. you can quickly see which router it is connecting to by hold down the option key when you click the airport fan in the top menu area.. and look at bssid.. you will have to figure out which number MAC address relates to which router.
Also do not be surprised if Lion gives you issues. It seems to often drop out and lose connection to the TC as a backup device even if internet is still working.