Welcome to the forum! First thing you need to do is to have them sexed because you can keep a male and a female or two males but you cannot keep two females together because, eventually, one of them will hurt or even kill the other one. People will tell you they have two females together and they get along but I cannot begin to tell you how many times I've heard of people coming home and finding one of them dead even though they 'got along'.
Now, assuming you have a 'good' pair... One thing you need to know from day one is that you will never have the kind of relationship with them that you can have with a companion parrot. Lovebirds can learn to trust and love you, they will learn to step up, they will ride your shoulder, they will kiss you and maybe even cuddle against your neck but, after an hour or so, they will want to go back to the other bird. They are an aviary and very flighty species and you can't go against Nature. Having said that, it doesn't mean that you cannot have a wonderful relationship with them! I recently rehomed a pair of a female that had been found in a balcony and an ex-breeder male I got for her and, although the male had never had any real interaction with humans, he had learned to trust me and was even perching on my head and shoulders of his own initiative - I never tried to teach him to step up because, to be honest, I don't see it as a necessary thing. He came out every day for flying and went back into his cage on his own when I put the food there and that was good enough for me.
Now, as to taming them. One week of talking to them is nothing (and I do mean NOTHING). It takes months for a bird that has not imprinted to humans to learn to trust one so keep on doing what you are doing for as long as it takes to get them used to you. You will know they are when they get close to the side where you are sitting (your head needs to be at their same level always, never 'looming' over them) and take treats from your fingers from in-between the bars. The trick about the treats is that you cannot free-feed protein food (seeds, pellets, avicakes, nutriberries, etc) because, if you do, they will not be interested in the treat and if you don't have a high value item as a reward, you will never get anywhere with them in terms of training. So you need to switch their diet to something like gloop and produce in the morning (they LOVE greens and fruit!) and protein food for dinner. This way, you can identify the food they cannot say no to and use it only for training rewards (most likely, it will be sunflower seeds).
I am a bit confused as to their cage... is 57 the height and 18 the width and the depth? Because, if it is, I am afraid that the cage is not large enough for them. They need much more room than that because the vertical space is pretty useless (you will see that they spend all day long up on top). This is the kind of cage I recommend:
http://www.qualitydiscountcages.com/hq- ... cage.htmls.
So, let's recap: 1) sex them - 2) see if you can get them a flight cage - 3) change their diet and 4) keep on talking to them for as long as you can every day (you can also sing or whistle to them and even just sit watching TV or doing computer work - the idea is that they get used to your physical presence) and, after you have switched them to the better diet, you can start offering them treats from your fingers and allowing them to come out to fly for two hours or so right before they get their dinner (I could do it both in the morning and in the afternoon, after a while but start with dinner, only).