Ok. I'm going to answer your question, but I'm also going to give some advice first. I"m currently reading my 15th book on chess. EVERY SINGLE ONE OF THEM says that a person should not start working on openings until they are rated about 1800. If your ratings on chess.com are accurate, you really aren't rated that high, and neither am I really. Now, please don't take that as an insult because it isn't meant to be one. But there are several pieces of advice I would like to share with you based upon my readings, own experience, and your posts because you seem to be a little obsessed with openings.
1. A person should start with learning Tactics. I am going to assume your Online Chess rating is the most accurate which means you are rated about 1400. I would use Chess-tactics.org to get familiar with tatics and work with Tactics Trainer and the Polgar Chess book you mentioned in your posts to get your tactics rating up to 1400. Trust me, that will do wonders for your play.
2. Lean as much as you can about strategy BEFORE you get bogged down by the quagmire of opening study. I have the book, Fundamental Chess Openings and in that alone there are over 400 openings, not including different variations within those openings. Trust me when I tell you that if you get bogged down in this your rating will only go up about 2-300 points studying openings and then you won't progess any further. This is because of 3.
3. All the books and advice I have gotten from people play OTB and on chess.com is that Memorization is required in order to play chess. But Understanding is better than memorization. The reason being that you will run into a player who takes you out of your opening prep. And if you don't have any understanding of strategy when that happens, you will lose. Now best is Understanding + Plus Memorization. But Memorization of variations is not required to become a great chess player.
Nigel Short was a World Champion contender and he has always said his ability with memorizing openings is horrible. The same is true of Samuel Reshevsky, whom Bobby Fischer thought was the strongest player in the world in the mid 1950s even though both players hated each other. But Reshevsky often suffered time pressure because of his inability to study the openings. I even seem to remember reading that he could study an opening all day and not remember any of it five minutes later. And Reshevsky beat Capablanca, Alekhine, Euwe, Lasker, Botvinnik, Fischer and Smyslov; all world champions.
4. Every great player I have read about says that you need to understand the ideas behind your openings. This includes Karpov, and IM Daniel Rensch on this site. The best way to understand the ideas and strategy behind your openings is to have a good understanding of strategy before you start studying openings.
5. Bobby Fischer said that chess was based on ideas, and he loved when someone, regardless of strength, new what they wanted over the board. This is where strategy comes into play. If you spend your time understanding strategy, you will be able to always have a plan regardless of opening. And having a plan will go a lot farther than knowing an opening out to move 20, because even if you get that far you will have to leave your preparation at some point, and then what do you do.
6. Everything I have also read was that a person can get to 1800 or so just playing correctly. This means properly understanding the primciples and strategy of chess. And I know that most people say that absolute rules don't work in chess, and it is the exceptions to the rules that matter. But in order to break the rules, you must first know and understand the rules so you know when it is ok to break them.
Ok. Now I will answer your question. First read the book Mastering Opening Strategy by Johan Hellsten. That will give you a great understanding of how the opening functions and the principles which need to be understood. Plus it will give you some advice on how to build a Repertoire. Second read, How to Build Your Chess Opening Repertoire, by Steve Giddins. It will help answer a lot of your questions about openings. Now some openings that don't require a lot of prep are "The London and Colle Systems." I use the London and I like it a lot. It's been used by a lot of world class players such as Kamsky, Petrosian, and Kasparov. But the thing you need to look out for with the London and the Colle is that you will not be exposed to a lot of different positions using them and it can hinder your progress if you use them too much. Finally another grreat opening book is the Dynamic English by Tony Kosten. It deals with the Englsih Opening with 1.C4, 2.g3. It also doesn't require a lot of prep.
Does anyone have any experience on "simplified" opening repertoires that can be played with a lesser amount of memorization (although they may not be simple, they are simply simpler than what a GM might memorize). One example of this is what Aww-Rats teaches in his video lessons. There are also books on other systems. What is out there and what looks good? How do they compare (if you know)?