I mostly play SR and i'm kinda getting bored of it, might play some Dominion for fast IP and for some variety. what champs are good?

All of them.

Most champions played properly can do well in Dominion. Except Eve. I wish people would stop playing her, 99% of people who play her are trash, and don't do anything productive for the team. Just play the champion that you are most comfortable with and look up guides if you must, but most champion's items don't really vary much from SR, for the most part.

generic advice:
if you're going top, play an 'assassin' (burst damage champ), fighter, or carry with high mobility--blinks, dashes, and in some cases movement speed steroids.
if you're going bot, play an extremely strong 1v1 laner. ability to push, kite, sustain, and kill are all important. also, it's strongly advised that you take a champion that scales well with gold.

examples of good champs:
top--kassassdin, leblanc, talon, fizz, shaco (ad), pantheon, wukong, riven, poppy, vayne, graves, and caitlyn.
bot--yorick, ryze, cassi, jarvin, heimer, urgot, and maokai.

note that the mage and carry champs i listed can pretty much go top or bot without issue.
edit: also, i don't really think that any champions are bad picks (unless they're not needed for the team comp). you can do well with pretty much anyone if you build/play them properly for the map. i just listed the more popular champs for each starting role.

Don't forget Cass! She's good anywhere.

Edit: Just saw you listed her on bot. *grumbles*. Ok, but she's still good on top too!

Gosh, all these free week Graves going bot. Even Rickless says top Graves is good. You have to take advantage of his AoE.

Most champs are viable on dominion with the right team comp. However you only really see the same 15-20 champs every game.

The champ that you get yelled at for picking in SR but that you love? Yeah, you can play it in dom. Sure, there are champs that are stronger than others, like the ones mentioned, but as long as it fits in your team's comp, you can play any champ.
Even Eve is a good pick as long as you FIGHT WITH YOUR TEAM, backcaping the entire game is the worst posible think you could do as any champ, but the stealthers are the ones that tend to be guilty of doing that. Forget anything other SR players, specially the dominion haters, told you. Roaming and backcaping is a terrible idea, tanky dps doesnt dominate, akali/trynd/jax/etc are terrible bans, etc.