As far as I see it, there are three categories of enlargers. 1. The amateur/enthusiast category, is comprised of enlargers built economically, to be sold at a good price, and are rather lightweight in construction with minimal accessories available. Usually 35mm, and sometimes 120 size negatives are the maximum size printable.
2. Are the medium-weight professional enlargers, the "standard" so to speak of a working darkroom, and usually take negatives up to 4x5" in size. Typical of these types are the Omega D series, and the Bessler 45 series. Extensive accessories, color heads, cold light heads, many, many different choices in negative carriers, etc.
3. The Big Boys, Very robust, often floor-standing enlargers that take 5x7 and larger negatives. These are the top of the crop. If your darkroom has the space for one of these bad boys, you have the ultimate, if you can pay the price. DeVere is one brand that comes to mind, also the largest Durst models, and perhaps other names.