I'm still very slowly cobbling together my darkroom. Our current rental has a bathroom / laundry room with a nearly perfect gap between the sink and the shower stall, and my father-in-law made a very nice table to fit out of scrap wood (he's handy that way), on casters so I can move it around. I had picked up an Omega B-66 for a song on Craigslist (enlargers come up around here for maybe $300 every month, $100 every quarter, nearly free yearly) and it had everything but the neg carriers and a MF lensboard.
I picked up a MF lensboard and plan on using my Great Wall lens for that. I was misinformed about C-700 neg carriers being backwards-compatible, so I bought one 35mm neg carrier that doesn't fit back in July, and one that does fit arrived Thursday. Red LED Christmas lights for safelights (already tested), some tray space on top of the washer and dryer, not enough room in the sink, but enough room that I can mess with "fiddly little negatives" (Leon's term that I love). And for a blue moon I've been wanting to try two vertical 6x9 diptych contact prints as a 4x6 landscape. With any luck, today or Sunday should be the day.
But, the gist is the slower you go the cheaper it is. Stuff will trickle in via Craigslist or evilBay, you'll see things at the store and think about it in a fresh context, people will hear about it and give you things (I have two darkroom timers now), and it just slowly congeals. More than once I thought too long about buying something and two or three weeks later one nearly fell into my lap.
For me, the whole issue around neg carriers seemed to be the biggest deal with a used enlarger. Some brands have really good interchangeability across the ages, some less so, some (like the Omega) very good across just a subset of the models.
I ended up using the same online references as Francois when I finally got my neg carrier act together.
Best of luck!
-Jack
P.S.
On a sidenote, I'm pretty darned sure that I used a B-66 in college. I was fiddling with it when I was setting it up, but reading some manual I had pulled up on my phone, and my hands went to the right knobs without looking and it stumped me. I squinted and tried a couple of things and either it was some other enlarger with the same layout or it was a B-66. Either way, felt like an old friend. I can almost smell the chemistry. I was never great at it, but the darkroom always felt like the womb.