The latency issues that you are thinking about would be linked to satellite internet or internet provided by a cellular company...
Having a wireless network in your house isn't really going to give you any kind of latency as long as you are well within range..
I typically play on my PC in the garage and it's connected(wireless) to my router in the house on the 3rd floor..
No one has ever complained of warping and my net status is pretty stable..
You will not have any issues using a wireless router and a wireless card in your pc.. You are on your own network using your
own internet connection... If you start to get out of range, then you'll have issues.. But if you're within good range(within 150 ft indoors and 300 ft outdoors)
you will have a stable connection that won't drop out and it will be just like you're on a hardwired network line...
There's no need to get a 2nd DSL modem.. Share the connection you already have..
Don't run a cable.. Wireless technology is equivalent to cable if used properly and is very secure if you set it up to be..
There are bunches of us here that would be more than happy to guide you in this endeavor..
