[beerrat]

I'm planning on making a lite lager as a base for some session beer flavor experiments. 
I have a lot of corn sugar, but most recipes seem to use rice as the adjunct instead of corn.  The BJCP style guide indicates corn ok.

What is the different flavor profile corn vs rice will contribute?

[Kaiser]

corn sugar is  100% glucose whereas rice syrup has a sugar profile that is closer to actual brewer’s wort. I.e. you get a mix of glucose, maltose, maltotriose and so forth.

I'd go with rice syrup. But you may also be able to use up to 10% corn sugar to lighten the flavor.

Kai