Marco was okay, but he was... well, he was too white.
Jake's hair was a bit too styled. He looked less like his character and more like eye candy, but that's understandable when you're using google images. What pops up is the stuff that people like, I suppose.
Erek was okay. I pictured him with blonde hair (like I do with a lot of book characters because my own hair is dirty blonde) but otherwise, good choice.
Tobias... I pictured him as a weaker person. The guys you chose were ones that looked pretty manly, but I saw him as a bit more feminine.