I'd read all three of those. It's a lot. But well worth it. I'm kinda going through the same thing right now. I'm not even letting them see each other until both or fixed. And the. Waiting 4-6 weeks to start the process. Do not listen to what most stores tell you and just put them together.
Two males are a good combo. I used to breed and show Flemish; I retired and neutered them as they aged up. Sam and Max were the most inseparable couple even though they weren't neutered till they were 3 or 4 years old.