I'd recommend Girl Friends, it fits the 4th type of yuri manga which you described.
It starts of with them becoming friends but then the protagonist falls for her best friend.
The manga is really funny and sweet but there are moments where it becomes quite sad.
Give it a try, it's my favorite yuri manga.
If you already read that then I suggest Blue Friend, manga by Morinaga Milk(most of them are yuri or shoujo ai), and Kimi Koi Limit(it's a love triangle, I think it's not complete yet).