Hello Rivendell.
Great suggestions and advice above. As for the chemical pH adjusters I don't recommend them at all. They are unstable and can even lead to a pH crash before you know it and could result in fish loss. Too, as mentioned it has to be added for the life of the tank. Here is a link concerning pH:
Properly Maintaining the pH in a Freshwater Aquarium - Rate My Fish Tank
It also suggests natural methods of lowering your pH. I think you'll find it very helpful.
You will have a much more accurate reading for your pH if you let the water set for 24 hours then test it. You'll have to test the pH level in the tank once you get it, or test the pH in the bag or bucket that the fish are in.
Here is a link concerning acclimation that may be helpful as well:
Acclimating Tropical Fish to Your Fish Tank
Depending on the # of Angels you have could result in aggression and territory issues. For a 55g tank I would recommend no more than 1 pair male/female. Too, as they begin to spawn the aggression could get worse.
Neons, I suggest they go into a well established tank. They can be very sensitive to change and acclimation is key here as well.
I'll be looking forward to some tank photos!

Have a good evening.
Ken