This might need re-writing
Especially as we are have gone through a,b,g,n and now on ac.
Keep in mind guys that while 2.4GHz has more interference issues than 5GHz, it also has a longer range. If you are having issues with interference change your channel too 1, 6 or 12 to avoid conflicting spectrums. Don't succumb too PC Worlds sale tactics that their overpriced 5GHz routers are unstoppable
You will only be back the next day too buy Home Plugs!
If your buying a new router look at 802.11ac, it is capable of up too 450Mbps (reportedly), and has an awesome range on it. It is a tad pricy at the moment (£100 mark +) but they should be a reasonable price by Summer.