Samsung has a cover that I can personally confirm fits my S5 with the Qi back:
"Galaxy S 5 Protective Cover, Clear" (EF-PG900BSESTA)
Galaxy S 5 Protective Cover, Clear
Samsung lists it for $25 but you can buy it for $15 by ordering it from Staples and choose In-Store (free) delivery. It fits like it was really designed for the Qi back and it doesn't interfere with Qi chargers.
All that said, I will probably buy the Diztronic cover when it comes out. The Samsung is rubber that is so non-slip that it almost feels sticky, and I'm not in the habit of dropping my smartphone so I'd prefer a smoother finish on a cover.
Ted
PS: A lot of folks really like the Tylt-Vu charger but it's some $70 on Amazon. I found one out of Hong Kong that seems to be the same, for $30:
A6 Qi Wireless Charger Charging Pad Transmitter for Apple Samsung Google HTC LG | eBay
My wife and I each have one and we really like them. In fact, my wife has a Qi receiver in her S5 rather than the Samsung Qi back and it can be quirky connecting to some Qi chargers. But it
never fails to connect to the "A6-Qi" charger. According to the box it has three coils like the Tylt has. I just ordered a third one for my desk at work. Edit: It takes 10 days to get here from Hong Kong.