Have a look around good aquatics shops are notoriously bad at publicising themselves and are often on an obscure industrial estate happy with the trade from word of mouth.
Colins put in some excellent points about water hardness - I've gone off the assumtion you have neutral water but if you can let us know either way it would help tailor the fish choices
In terms of the fish you have put on your orignal list they do seem that they are all quite common species, and species that can entail issues too so just wondering if you have considered alternatives to all of them? eg instead of the RBTS you could look at a group of Skunk Loaches though this might be an either or situation with the Pictus. The Parrot is actually a hybrid fish, which can be fine but there are other cichlids you could consider, top of my list would be something like a Severum, the red spot golds are really nice and just as colourful as Parrots but IMO a better looking fish and you could also look at Electric Blue Acaras which in combination with the Severums would look stunning the tank is probably big enough for a few of each species.
In 165 gallons maybe a stock list of something like
2 Red Spot Severums
2 Electric Blue Acaras
10 Dension Barbs (if you wanted to keep this tank Amazonian you could look at Red Stripe Hemiodus or Annostomus Ternetzi if you can find them)
8 Spotted Silver Dollars
6 Pictus Catfish
1 Pleco (a common would be good but you could look at a fancy species like a Sunny or a Royal?)
Plants will be near impossible with Severums and Dollars so go for a sand substrate with loads of big chunky drift wood.
Wills