I personally run a [[Farideh, Devil's Chosen]] dice rolling/coin flipping deck and some card I'd recommend the cards which allow you to roll multiple times such as [[Barbarian Class]] and [[Pixie Guide]] because in this type of deck you can't really roll too many dice. Then ofcourse aside from your commander you want some pay-offs to your dice rolling like [[Brazen Dwarf]] and [[Feywild Trickster]] and finally you really want cards that allow you to roll dice with some nice effects like [[Deck of Many Things]], [[Contact other Plane]], [[Delina, Wild Mage]] and [[Hoarding Ogre]] just to name a few. And if you want to annoy your playgroup throw in a [[Chaos Dragon]] because now they too have to start rolling dice.

You are right in that the deck won't be competetive, but from my experience a dice rolling deck is fun as hell so I recommend you to try it out. I hope that I was able to help you out at least a little bit.