I am having so much trouble deciding what bit for my mare. She have a fat tongue and does not like single jointed bits. I used a low port however not sure if that would be best since I am going to have to refresh everything now that we got her back. She chewed on my 3 piece junior cowhorse that I though would be better because I thought about ordering an o-ring dogbone snaffle. I am just not sure. The only low port bit I have has a shank. 

Can you use a hackamore?

Try something with a chain mouthpiece.  People instantly think oh no a chain, but it is flexible so it just lays in your horses mouth. 

Doy you think it would be better than a low port?

The low port gives you a little more lift then a straight chain.  Most of our horses are comforable in the straight chain bit.  Because the chain lies flat on the tongue, but has some flexibility, it seems to be comfortable.

If you feel you need the port, go with a chain port.  Here's a Jr Cow chain port. 

I had a gelding with a thicker tongue and he really like the Billy Allen mouthpiece.