Ok that Rollei/Nikor has a dichroic color head and should take a bulb available from any of the internet bulb vendors. If the Omega has a condenser head then I'd say the Rollei/Nikor is the one to keep for 2 reasons: 1) Diffuse light minimizes dust on negatives and 2) the color head is perfect for multigrade B&W printing.
That 50mm/f4 lens is a 4 element lens. It should be fine starting out but some day you could replace it if you want to do big enlargements.
I think that enlarger uses this bulb (EFP) https://www.interlight.biz/light-bul...&ID=FROOGLE-US
They also made a condenser verion of that Nikor enlarger. I'd say you got the better one (but there are a lot of condenser fans out there) so I'll say you got more expensive one