Reverse osmosis whole house system RECOMMENDATIONS needed

I have a $1000 kitty to spend, but unfortunately I want 4 things that will run me well over that. They are a Vitamix (or like product), quality hepa air filter, quality non-poisonous cookware set, and a whole house reverse osmosis water filtration system. I figure I will try to get 3 of those and get the 4^th one for Christmas. But I need help on getting quality products, but spending as little as possible. Maybe I can save a few bucks by getting a used Vitamix. I need advice on all products and places to get them.

But specifically I want to info on what to look for, what to ask, and what to know when buying a reverse osmosis system. Like what happens if I take a long shower or let the water run for a long time? Most importantly what is the minimum price I will have to pay to get a quality system???

Also about a whole house water filtration system does anyone have anything negative to say or something to watch out for, regarding reverse osmosis?

Thanks for your help regarding any of these products.

Minnie