Hi mootime
I too struggled with pro points - not the easiest to get your head around at the best of times, let alone when you have a newborn! Out of the two I would suggest slimming world. They kind of still do red and green days, but I think most people follow extra easy (fruit, veg, meat, pasta, rice and potato are all free - you get healthy extras to get in your diary and fibre, and have to syn everything else, including cooking oil and sauces). As a breastfeeding mum you can have more healthy extras to get the milk/calcium that you need. It's slimming world so you can eat as much of the free things as you want (afternoon snack - banana with a toffee muller light yogurt?) and syn things like chocolate etc.
It should be fairly simple for you to follow whilst breastfeeding - sit down and go through all of the books etc, and make a list of free foods for your fridge. Then if you are in dire need of something to eat mid-afternoon, it will be easier to make a choice that will match the programme.
Oh, and the idea behind slimming worlds extra easy is that all meals should be 1/3rd fruit and/or veg.
Definitely don't think about it for a little while. Perhaps get the books from slimming world so that you can start to make healthy choices (if you don't already) but don't think about the actual weight loss yet. Your body needs to establish you milk supply properly first. And you will be tired!! Focus on bonding with your baby, and resting when you can (this will help with the weight loss [really!!!] - if you don't get enough rest you will reach for high calorie, high fat food like chocolate just to get your through the day!!)
I wouldn't start thinking about focusing on your weight loss until you are in a settled routine with little one.
Enjoy this time with your baby 
x