The Garmins are very nice units and I have no hesitation in recommending them.
But you may need to consider a few things:
Can I mount it such that it doesn't interfere with control movement or instrument scan?
Can I use on-board electrical power or do I need to consider the battery autonomy?
Can I mount it such that the aerial has a good view of the sky (and preferably is shielded from the ground)?
Is the display bright enough and big enough to be easily read in the proposed location?
All these factors could affect your choice.
If possible, borrow some examples of the models on your short list and give them a practical trial.