I failed to mention a couple of other things.
1) I don't think you are actually able to TURN OFF the wireless features of the wireless router. What would the purpose be to make or buy a wireless router, only to turn off the wireless features ??? The best you would be able to do is to set up the wireless with the best security you can. A) Disable broadcast of SSID. B) CHANGE the SSID from the default (I forgot to mention this in the earlier message) C) Use MAC filtering D) Set up the WEP/WAP encryption to toughest level. (There might be something else I am forgetting still)
2) Regarding compatibility, you CAN mix-and-match components--for the most part. I have a Motorola cable modem, an Asante 4-port Ethernet router, a Belkin 802.11B wireless router, Dlink NIC's for the computers, and I fogot what kind of 802.11B wireless USB adapter. All get along fine (except I accidently deleted the drivers for the USB wireless adapter, and I can't find the driver disk, and I don't know who makes it). When you get into the wireless aspects of the hardware, you need to pay attention to the different 802.11 protocols. 802.11B was first (I think). I don't remember the transmit speeds, but it has a range of only about 150 feet, sometimes less depending on the type of material it is trying to transmit through (the walls, floors, metel or wood). 802.11A was next, but not compatible with 802.11B. The 801.11A either had better range, or speed. I don't remember which. It doesn't seem to have caught on as well.
Then came 802.11G , with better range and speed than the 802.11B. But it is also backward compatible with 802.11B (like Win98 was compatible with Win95). But when used together, 802.11G will only run as fast as the 802.11B could run. AND some of the 802.11G makers add extra features that only work with equipment they make. Read feature lists carefully.
Finally, there is a pending standard, I think they are going to call it 802.11N. You might hear of a product being "pre-N". I'm not sure if these features are compatible with 'regular' 802.11G features or not. At best, they might be only partially compatibe, like between 802.11B and 802.11G.
So there you have it (I think).