As of right now I am a 35mm shooter. I hope to move / try out medium format at some point. But I don't foresee that anytime soon.
Another question regarding Enlargers.. Do the lens' matter much? Do all enlargers have a universal thread mount? I understand some might need a lens board. But they all seem to have threads on the end of the lens.
Yes - lenses matter.
For 35mm, a 50mm lens is usually best. There are/were many different ones made, and their quality and price varied as well.
Lenses also vary a bit with respect to thread size.
A 39mm thread is the most common - particularly for relatively modern 50mm lenses.
The lenses attach either to the enlarger/lens board/lens mount in two main ways. Some lens enlargers/lens boards/lens mounts are threaded themselves, and the lens screws directly into those threads.
In many other cases, the lens boards/lens mounts have a hole in them that the lens threads protrude through. The lens is attached to the lens board/lens mount by screwing a retaining ring / jam nut on to the threads and thus pulling the lens body into contact with the board/mount.
To give you a sense of how complex this can be for larger format enlargers, and to give you a sense of how many lenses are out there, here is a lens mount reference link for the Omega D5 4x5 enlarger. That enlarger uses plates which attach to boards or turrets, which mount easily and quickly to the enlarger chassis. T
he enlargers you are considering will be simpler - don't worry!
http://www.khbphotografix.com/omega/LensMountD5.htm