So many choices and so many opinions/favorites
You're lucky you don't have at least a hundred replies by now, each recommending a different combination
I do most of my printing on Ilford MG fiber and RC, for me, they are quite consistant with each other, so proofing on RC and doing final prints on fiber works. I wouldn't recommend doing it that way mixing brands or types though.
Many, if not most enlargers have some sort of arrangement for slide in filters above the negative, with the possible exception of some with color heads, in which case it's irrelevant anyway. If you somehow end up with one that doesn't, then Ilford MG filters are available that go below the lens and come with a holder that fits onto the lens mount. I would stick to enlargers by Omega, Beseler, Durst, or perhaps Saunders/LPL, although I'm leaving out many other good candidates, and I'm not listing them in any particular order. Of those, Omega and Beseler are the easiest to find on this side of the pond, Beseler 23C's practically fall out of the sky.
Durst never sold their products here on a consistent basis, thus aren't as common, but they are generally excellent, and would be my first choice for doing MF in a temporary darkroom.
Keep an eye on Craigs list or do a wanted ad there, and an enlarger will probably fall in your direction. eBay is a possibility too, but you'll likely do better with Craigs list, the apug classifieds are a good source too. Look at ebay completed auctions to get an idea of pricing, but factor in shipping. On ebay watch in particular for items that require local pick up, there aren't so many of those here in the Northeast, but they occur. Shipping on enlargers is steep, because they require pretty large boxes, and the baseboards are always heavy. The local pickup required auctions eliminate most of the competition however, so the prices are much lower and you don't contend with shipping costs.
barry