You should definitely get two as they are very social.

You won't have any problem with keeping two males together. I would buy them as litter mates or gets them young and put them together. Rat breeders sell them in same sexed pairs so they always have a buddy. Male rats will play and groom each other. A hairless and furred will be fine. I have heard the hairless may have scratches on them from rough housing, but normally nothing serious.

Every man needs another man to share his mancave with.

Enjoy your ratters! They are a lot of fun and you will definitely get attached.