I have been satisfied with the basic 45M's, and its only in this new era of low priced used darkroom equipment that I decided to upgrade in some areas.
Bought my 45S-VXL for 200 bucks on ebay with the MODULE that actually works. Best Enlarger I ever worked with, not to say there aren't better. If I had to replace it though would go with a Durst. Only to see if it is truly better. New to the Forum and look forward to discussions. Am currently on another forum that is for LF but seems many discussions deal with topics that are Taboo here, and for which I am not interested.
I have a 45-VXL I got off ebay for $250, and it arrived in great shape, amazingly. It has the motors for focus and height. It's a great enlarger, really pretty excellent overall. I've used the 45M-series extensively in the past and the VXL is defintiely better. Agreed, alignment can be fiddly but if you are patient it's not bad, really. I use it with an arista cold light head for B&W and a Minolta/Beseler 45A head for color (which I think is the best of the beseler color heads, easily. And they are dirt cheap these days, on ebay. ). Overall, I think it's the best choice in 4x5 enlargers that are reasonably available, reasonably priced, and with good parts and accessories options.
Any interest in the Bessler D5-XL Enlarger? I have an entire Color/ B/W darkroom for sale. My items are in pristine condition.
Timer, negative carriers 2 1/4" and 35mm, 80mm lens, micro-sight grain focuser, super chromega dichroic II head, enlarger base, plus much more. Can do murals. It is an amazing darkroom. I'm in NYC.
I'm hoping to find my darkroom a good home.
Enlargers are coming up in house & lab sales frequently now. Often, they are lightly used.
The CB-7 is a remarkable machine for heavy production in all formats up to 4x5. It can be had for low three-figures, and would be a good item for your list of possibilities (if you have the room and someone to help you carry it).