I bought the little Sony HVLF20M flash a while back, but I find it just doesn't have enough punch. Looking for a replacement, I was about to order the Nissin i40 when the B&H site suggested the Metz 52 AF-1 model. I was surprised to see it is now available with a dedicated Sony foot. I've used Metz products since the 70s and always found them to be excellent, so I ordered it without hesitation.
I especially like that it covers the 16mm end of the 16-35mm zoom with ease (using the flip-down WA lens).
I was happy. I got even happier when B&H emailed (after I'd already ordered) to tell me there's a $60 rebate, which makes the net price about $190; only a little more than the wimpy Sony. So, if you're looking for a 'real' flash for an a7, here's the info.