Tanks are cheap, even new. A plastic tank with two adjustable reels can be had for less than $25 from Freestyle or any other large retailer of darkroom gear. The Beseler and Omega enlargers are both first rate machines, and the Vivitar enlarger isn't even in the same league. To put it bluntly, the Vivtar is a piece of crap compared to either the Beseler or Omega units. Yes you can use it, but you'll outgrow it fast. I had the same enlarger with a Bogen brand plate on it and it was just awful. I gave it away to a friend who wanted to try his hand at the hobby. He's since passed it on to yet another newbie in favor of a better machine. Of the other two offers, I think the Beseler is the better of the two. It looks used and dusty, but it's a solid machine if it's in good shape. The safelight is worth as much as a tank, and you'll need one of those too. The Omega is very nice and almost the same as an old B600 that I"m using to make small prints from 35 mm negatives. I like that little enlarger - a lot. When all I want to do is make 4x6 or 5x7 prints from 35 mm negatives, it's so much easier than cranking up either the Beseler 45MX II or the Omega D4 that I have in the darkroom with it.