I am creating a website with discount coupons and contests.

I am creating a website with discount coupons and contests. In discount coupon post I am displaying some elements and in contests I am displaying other elements. So I understand they have to be 2 different "Post types". My question is how can I have a blog displaying all posts types

Contest 1
..
Contest 2
...
Discount Coupon 1
...
Contest 3
...
Discount Coupon 2
...

Is there any way to mix different post types in one blog feed? Or I have to create in one post type, put all things inside meta-boxes and have two templates and select what template (contest or discount coupon) ?