Hi Joe,
There are several Shure 'Unidyne' models - probably the most popular is the 545 which is indeed a Unidirectional type, as are all the 'Unidyne' models. The clue is in the name
I use a Sony Electret Mic directly into the Mic input on the KN7000 in conjunction with the KN7000's Mic Effects - usually a little Reverb - and have achieved very good results, when producing a CD. I hasten to add, that I was not singing - only playing the accompaniment for a vocalist friend. The recordings were made via USB and the Goldwave sound editor.
When I had my own band back in the 60s/70s, we tried many different microphones, including Shure, Reslo, Beyer, AKG but we finally settled on the Sony Electrets.
I like the Sony Mic because it produces a good all round sound - smooth bass and crisp treble, especially when using a 'close mic' technique and it also has excellent anti-feedback properties.