I wouldn't call Justbet a 2nd tier book because it has identical lines to bookmaker.
Betus will take opinions, but you have to be very careful with them. Angles and grading "errors" are quite common, and they limit winners. CS is awful.
GTBets will take opinions, but after you hit a few they will limit you quite harshly.
Everygame will take the occasional opinion. I have never tried to cashout from them, and I know there have been complaints on forums. Search around before depositing.
WagerWeb is affiliated with Heritage. If you're limited with Heritage they won't let you open an account. Like a lot of offshore books they have sleazy CS.