I would recommend against the atomic. They are great regs very well made but they don't have the dealer and service network that aqualung/ Alex or scubapro does.
Being new you likely don't know for certain where you are going with this sport yet or you might change your mind in a few years and change direction you might move etc.
If you move start traveling etc chances are wherever you are there will be a scubapro or aqualung/apex place close by that can service your reg if something goes wrong.
If possible see if your local lds will let you rent or borrow the models your considering try them out which ones feels the best to you, "fits YOU best", that's the one for you.
Other than that I would recommend a environmentally sealed in case you decide to do cold water diving.
Being new you likely don't know for certain where you are going with this sport yet or you might change your mind in a few years and change direction you might move etc.
If you move start traveling etc chances are wherever you are there will be a scubapro or aqualung/apex place close by that can service your reg if something goes wrong.
If possible see if your local lds will let you rent or borrow the models your considering try them out which ones feels the best to you, "fits YOU best", that's the one for you.
Other than that I would recommend a environmentally sealed in case you decide to do cold water diving.
