If you have the time, please go to wholesomebabyfood.com and read the section on starting babies with solid food.
To answer your question, yes, you can mix those items with rice - in fact, you can make all sorts of combinations. Your baby won't know what's inside unless you make funny faces.
Each time you introduce a new item, you need to follow the four day rule. Once the item is clear, you can mix it up with either a new item or a cleared item. If it's with a new item, then you keep track of the new item for four days. For example, I intro rice for four days. Then intro peach on its own the first day, then mixed it with rice the next three days. Then I intro pumpkin with rice on first day, then pumpkin with peach on next day, then pumpkin for two days.