Overly bright dots are a problem in cheaper red dot finders. Is there a way to dim it?

An illuminated 50mm RA finderscope is kind of overkill. ScopeStuff sells them, but they cost almost as much as your telescope! You may want to go with one or the other, illuminated or right angle.

Looking at your options, I'd still go affordable and choose either a 6x30 or 8x40 illuminated finder.

The dovetail base needs to attach to the tube. I have not actually seen the model you have up close, but you may need to drill holes into the tube.

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