Looking for effetcs

I currently have a Mesa Roadster and looking for an effects unit that is easy to use and install. Any suggestions?

I recommend as few effects as possible so you don't mess up the tone of your amp. Maybe a delay and a mod pedal in the loop.

If you simply must, a Nova System might work for you.

To answer your question, in the past I've used the following in terms of FX units: (a) various Lexicon reverb and chorus racks, (b) TC Electronic G System.
I liked the G System, but sold it because it was more than I wanted. The Nova would be a fine choice as well. I do like the Axe FX XL currently. However, if you don't care for the amp & cab modeling, then wait for the FX unit that is due to come out should you need something that "robust."

But hey, no one should tell you how many effects you "should" or "should not" have. I've gone through many cycles over the past decade or two where I loaded up on FX, stripped down to straight-into-amp, back into huge pedal boards, then replacing into racks, then to Axe FX, etc. Go with what you want. Experiment. It's a (fun) journey after all.