Slim, Garrick, Musashi, Tanya, Tholin, Jasmine, Gizmo, Vincent, Bloodspear, Ezio, Osiris. I think I covered everyone needed for HoL, I may be forgetting a boss hmm...
What level are you? If you are under purple fusion, stick with physical, Tholin/Riley are pretty powerful at these levels. I highly recommend staying away from Magic heroes until after purple fusion.
I will tell you something I learned when i power-leveled one of my *other* accounts. Tholin is ridiculous at early levels, actually it's his wolves. Each wolf poison shot does nearly as much as your heroes ultimates at low levels. Gear him up and go destroy =)
CoF does get frustrating in regards to items, I completely agree. CoF is really only for gold, the item system is just a carrot on stick attempt to keep you going. When/if CoF sweep is added, all will be well =)
Unfortunately Soul Hunters actually has the worst item rate compared to the other MOBAS. The rest are 60 while SH has theirs at 80, i dislike this move very much.
This is just the way these types of games are, they will never change. If the drop rates were that high people would be capped extremely fast, get bored and quit.