Well the issue with the wired dropping. Could be a bad cable, could be a bad network port on the router or the computer. Or could be the whole router itself. Any event if wireless is what you want: easiest way to get wireless is with a USB wireless dongle. You can get wireless G capable ones for about $30 I think. Or you can get a wirless pci or pcie card. But if you dont know what a pci card is, then get the USB one.
5 or 6 things on a standard router is a bit much. You may see disconnections depending on how heavy the network use is. From what I've seen, dlink have some fairly reliable wireless routers. My suggestion is to google for specific models of wireless routers that are reliable, as most of them arent.