Marco, the DeVere 504 and 507 models that I have used and the 504 that I own, have all been soft, so to speak, regarding VC paper contrast settings.
I have come to the conclusion that the DeVere enlargers fitted with the Dichromat colour head, start to run out of contrast around or just over grade 4, compared to using the Ilford filters in a normal B&W diffused head. You are generally told that a colour head should get you to about grade 4½; I think grade 4 is closer to the mark.
That said, you just need to develop negatives accordingly and you will find no difference in the final outcome, the print.
I have been using my 504 enlarger for colour and B&W printing for the last 8 years, prior to that I did use them for a period in the eighties in a commercial lab. You can literally switch seamlessly between B&W and colour; the processing is the only complication and of course simply changing the filter combinations with a colour head.
I have used a dedicated DeVere original B&W head on a 507, it was slightly better regarding paper grade possibilities, but that was the only difference. The very best enlargers I have used for B&W were a tabletop DeVere 504 and a Beseler 4x5 side by side on a bench, both were fitted with the Ilford B&W head, they were fast, and very precise with regard to filter variations, but were prone to failure and needed servicing about every six months or so. They were working about 14 hours solid each day, which is why they had niggling problems!
One thing you may need to consider is darkroom size. I just did a quick measurement of my 504 free standing enlarger. You will need to allow 2.5m in height, the baseboard is 90cm wide, the depth (front to back) is 1m. If your ceiling height is a problem, and you just cannot raise the head all of the way, you simply drop the baseboard a notch or three.
You could reduce the width of the baseboard to about 80cm by either cutting the existing one, or making your own baseboard. The baseboard on my unit is just a board that bolts to the frame supplied, simple as that. I made my own board up by purchasing some MDF covered in Melamine on all sides. All four baseboard mounts allow for individual up and down adjustments, this allows for precise alignment. In fact virtually everything on the enlarger can be adjusted in accurate and easy steps with simple tools.
You will not regret purchasing one of these enlargers; in fact, I dont think you will have to purchase another enlarger once you have a DeVere.
Mick.