There are several things you need to change in terms of your mindset:

1) "I make excuses/reasons to meet [the girl]"

Why make excuses? Tell her straight up, "I think you're cool, I want to hang out with you and get to know you better". She can either say yes or no. If you're not bothered either way she's more likely to say yes, and even if she doesn't, she's no loss. This brings me neatly on to my next point.

2) "They are the one in 100 type of quality"

No they're not. An important thing to learn in this process is that no woman is "special" or "truly unique" or "one in a million". Au contraire - go into town on any given night and you will see anywhere from 10 to 100 girls of real 9/10 calibre.

Anyway, it's good that you're asking for advice. Your journey starts here my friend!

I'd say to make sure you get this chick's number before you try to arrange a meet. Let's be honest, meeting some random guy who she met on the internet is not going to sit well with her, so get her number and have some text banter back and forth (see the numerous threads on text game) and maybe even ring her. The best way to do this is to say, as part of a normal text "I'll give you a ring later, we can arrange something" and then ring her.

Just remember to play it cool and don't get heavily invested in this chick. She's just one girl and you'll do yourself no favours by being outcome-dependent. After all, you're the coolest mother biatch on the planet - she should be fishing for your approval. Other than that, be strong and decisive and try to avoid the typical "how are you, how was work" boring chit-chat. If she starts on that, a good thing I like to do is cut across and say "you don't really want to know that, let's talk about something good. If you could go on holiday anywhere in the world, where would it be?"

And as for the Mother Hen bitch, just ignore her. She's just jealous that you're giving her hot friend attention and not her. It can play to your advantage - use it to get your girl jealous. There's no harm with a little healthy competition, and it's nice to have a choice. And if you're really not into this friend (ie if she's fat and/or ugly) just tell her straight up. Don't make any apologies - you can't help if you don't like her. She should just accept it and move on the same way you would.