You actually need both
A7 for manual lenses
K1 for AF and best IQ and usability
My A7 is modded with the Kolari thin filter mod, in fact, its a mark lower if its w/o this mod imo. (for my needs, so YMMV).
Its my digital ME camera and exclusively for Pentax MF lenses as well as for RF and other orphan mount lenses.
Since its like a digital ME, I don't menu dig much with it.
AF is slowish (as many CDAF cameras are despite the marketing claims year after year; circa 2014)
Its only faster if you expand the CDAF area, but that increases the margin of focus error since it will look for the most contrasty item within the focus box.
K1 is way above the A7 in usability and IQ.
The downsides being size/weight and no EVF for MF.
On the latter, its ok if I am shooting slow stuff like landscapes and still life since the LCD works fine for these.