You need a low impedance microphone, which gives you a WIDE selection. Keep in mind that this is ham radio, not broadcast. You don't need to spend a king's ransom. Heil and others make works of art but, 99.9% of the time, the station on the other end isn't going to be able to tell the difference.
When I use a boom-mounted microphone, I use a $20 RS #33-3038 (unidirectional, dynamic 600Ω) microphone. The specifications compare favorably with more expensive microphones. I've received many unsolicted comments, saying it "sounds as good as a Heil".
I spent $50 on a low-rise long-reach boom (Hercules #MS540B). I use a floor flange and short section of pipe to secure it to the corner of the shelf above my wide operating table.
But, most of the time, I use a headset (Heil ProSet Plus). No matter which way I turn my head, the microphone is ALWAYS in the right spot. Like a boom-mounted microphone, it leaves my hands free and (most importantly) doesn't occupy valuable operating desk real estate. Unlike a boom-mounted micrphone, there is no mounting to deal with, and it blocks out background noise (which can be good and/or bad).
With both microphones, I use the Heil FS-2 footswitch (about $40) to keep my hands free to log & operate the rig. There's cheaper out there but the FS-2 is built like a tank and has two microswitches (one for the rig and one for an amplifier).
I use a MXL990 condenser mic and it sounds great. You will need some sort of preamp such as a Behringer VX2000 to provide the power for the mic and enough signal for your rig. I think I paid $50 for the mic from Musician's Friend
Tom - AB3FL
I may not know CW, but I can operate a boatanchor!