Hugh

Affinity may work for you.  IT's like 30.00 US.  They have a free trial.  Give it a shot.  Though this program is not a photo storage app, but more photo adjustment.  
 
May I suggest you continue using "photos" on your new Mac, and then an app like Affinity to do some of the heavier lifting you may need to do down the road?

I just ordered the 50-230. Haven't received it yet but decided on it because of 230mm tele capability...longest except for the 100-400 which is presently out of my $$$$ range. Found one used, I'm paying almost $550 less than I would for a brand new 55-200. I'm going to see if  4.5/6.7 meets my needs. The samples I've seen on line indicate it might.