Is an AirPort the solution??

I am so tired of having wireless issues!! In our 2.5 level house, we have the following computers and devices that need internet: a desktop PC, 2 windows laptops, 1 MacBook Pro, an iPad2, 2 iPod touches, 4 android cell phones, a Roku 2, an Epson Wifi printer and a Wii (though we have given up on getting the Wii to connect at the same time as the rest.) We also have tried to add a Wifi booster and/or an access point to try to boost signal in other rooms and have not been successful in getting either of them to work. We have a Netgear WNDR 3400 router. The access point and Wifi boosters we bought (and have never successfully used) are the LG-Nortel ELO AP300N Wireless Router and Access Point and the ZyXEL WRE2205 Wireless-N WiFi Range Extender respectively. The desktop PC is hardwired to the router. We also have a 1TB external Buffalo harddrive that is hardwired (It can be connected to the router via usb or ethernet.)

The problem seems to be the security settings (I think!) My husband feels strongly about having strong security in our Wifi, so we use the MAC address filtering as well as the WPA2 (or whatever). The problem is we can't get all devices to connect on the same security "channel" and stay connected. The one we are using now is the best, but I consistently lose the ability to connect on either my iPad or my MacBook. Both will randomly stop connecting to the router, even though it can find them (most of the time) and the only solution is to restart the router. I think that that part is the DHCP, but when the "Renew lease" button actually appears on the iPad, it doesn't help to click to renew it. I think he would be willing to let the MAC address filtering go, if that was the only option, but he definitely doesn't want to let go of secure settings entirely.

I REALLY want to find a router (or a solution) to be able to connect all of these things to Wifi and have them stay connected. I would really like to be able to connect the access point and/or the booster as well, so my signal is better throughout the house.

Is an AirPort the solution? If not, does ANYONE have a solution????? I am open to just about anything (short of replacing/reducing the computers/devices we are using.)

Thanks for any advice!!

Karen

Edit-- I realized I forgot one-- we also have a Kindle Fire!