I'd leave Powerline as a last resort. In theory it's a good idea but in practise they'll get nowhere near the headline figures and depending on your wiring may give you such a poor connection that you'd be better off with iffy wireless.
I like Ubiquiti wireless stuff, I have 3 of these in my large 4 bed house and I get great signal all over the house and in the back garden. In addition to the access points you need something to act as a controller but I can tell you more about that if you're interested.
My brother has the new BT HomeHub and it's pretty rubbish, the wireless range is marginally better but the throughput tails off very badly so whilst there's a signal in all the bodrooms the throughout isn't good enough for Netflix to work reliably. He's getting a couple of the Ubiquiti access points I have.