Cisco would be top of the line and as such alot more expensive, but I don't think you are looking at a quick fix either way.
Wireless N is the fastest you can get, double G not to mention it is more powerful (covers easily 3x the distance) but to get the equipment to do N will be costly as every device would have to have N. However, I believe routers that do N can do the older protocols as well (but double check to make sure).
What is your connection to the internet? Just double checking, but your bottle neck could be your internet connection and not your network. In general, I think its going to be hard for the average person (you are above average with all your devices) to put a strain on a home network. You can test your internet speed to see what it is (opposed to what your bill says) here
http://www.speedtest.net/ but keep in mind if you have cable internet you don't have a dedicated line and every time you do the test it will vary as your speed is related to how many other people are using the bandwidth as well.
Personally I would hardwire everything, I hate wireless and only use it for my laptop when I'm roaming the house. Its not going to be easy to find a router with more than 4 ethernet jacks, the best solution is to buy a GOOD wireless router and then daisy chain switches together to get enough ports. The size of the switch (they come in varying sizes 4-16+) is up to you but if you ever run out, just buy another one and connect it up.
Get a switch not a hub. A switch is a smart hub and will direct your traffic to the exact port it needs to go, whereas a hub floods all the ports with the info and the port that requested the information will take it while the others ignore it.