I also have a tiny darkroom. I've struggled with the space for several years and just recently bought a new enlarger and other equipment to make things a little more efficient.

First of all, I am prejudiced. I prefer condenser enlargers over diffusion enlargers. I've always used condenser enlargers except for one period of a little over a year when I used a Fujimoto color enlarger. I never liked the pictures I printed with it. Yes, condenser enlargers do make dust and scratches more apparent in the prints. But being careful with the film can minimize that and using Spotone is not hard to learn.

As a first enlarger, you will find condenser enlargers are cheaper to buy than color or variable contrast enlargers when new and are more plenitful used. If you're not going to shoot 4x5, there's no reason to buy a large format enlarger and it will take up a lot of your valuable space in that closet. You will also want to decide what is the maximum size print you want to make. You will need an enlarger that will print up to that size plus some to allow for cropping. From personal experience, I've had an enlarger that easily allowed for a cropped 11x14 from 35mm but I couldn't get to 11x14 with a full 6x4.5cm negative. So watch for those limitations.

Get good lenses. Until recently, I printed with an old Leitz Valoy enlarger I bought for $7.00 at a garage sale and a low-end Omega C700. But I used Leitz, El-Nikkor and Schneider lenses on these enlargers and the results were as good as anything done of multi-thousand dollar enlargers. The lens is more important than the enlarger as long as the enlarger is properly aligned and functions within your requirements.

I'd look for a used enlarger first. Make sure all the parts are included. Some enlargers use supplementary condensers for different formats and some have separate lensboards. You must have a negative carrier for your formats as well--some have adjustable carriers for several formats but most use separate carriers for each separate format. If you buy a color enlarger, it may require a transformer. In the long run, it may be simpler to buy new to be sure you get all the pieces.

Good luck.