Back to your original question ...
If you are talking about a Kenwood HF rig, I would not buy a desk mike at all. Good communications dictate a tight mike-to-mouth distance - no more than three inches. About the only way to achieve this with a desk mike is to either lean into it or pick it up. Leaning in is bad for the back, and most desk mikes are too heavy to hold comfortably.
That leaves three options:
(1) a mike on an overhead boom
(2) a mike on a headset
(3) the original hand mike.
Kenwood's hand mikes are hard to beat and mine is my backup mike.
The overhead boom lets you pick a variety of mikes and Bob Heil makes some excellent ones. If you know whnat you are doing, there are also excellent professional mikes that are available used at reasonable prices.
My personal preference is Heil's ProSet with the ragchew element. The sound quality is excellent; it is very comfortable for long peiods of use; you can keep the mike gain down and eliminate background noises; using headphones is the best way to eliminate distractions in the shack and keep the sound where it belongs - in your ears and not all over the rest of the house.
If you are talking about a VHF/UHF FM rig, it is harder to match an after market mike; just keep the supplied hand mike.
If you want to drop by and try out what I use, drop me a note. My email address is in my profile and I live two blocks south of the Inner Harbor.
Lon - W3LK