other alternatives include: for the ring bearer: a treasure chest a nautilus shell a teddy bear for the flower girl: colorful pinwheels banners http://www.sandsationalsparkle.com/Celebrations-Custom-Banner_p_11779.html
Here are some ideas:
http://www.sandsationalsparkle.com/Fleece-Blanket--Personalized--In-Various-Colors_p_1874.html http://www.sandsationalsparkle.com/Black-Accessory-Case_p_1890.html http://www.sandsationalsparkle.com/Camo-Travel-Mug-_p_15334.html
Having their photos on your bouquet is a great idea. Another one would be to assign seats for them and put their pictures on those seats during the ceremony. You can also have wedding photographs of the both of you with the seats.
I'm sure the JOP won't mind adding this to the ceremony. To make things easier, have your preferred readings in hand. If you're traveling, it's best to get a unity sand ceremony kit that's great for traveling like this: