T.S.
Let me offer my services. I have a family childcare business, and one branch of what I do for the community is children's entertainment. You may view my website at www.earthscreations.info for more detailed information and or call me to chat. I have a duck, rabbit, fire belly toads and a cat. All very children friendly animals that I can pack and move to be set up in a play pen scenario with feeding and petting opportunities. For the young ones. The children at my home day care enjoy these animals daily.
Also I have a wonderful mobile art studio that I could set up with tables and chairs and all that would engage children 2 and up to be creative and make wonderful masterpieces to take home from the party. I use open ended art materials so that every child has original creations from their own ideas rather that cookie cutter projects that all come out the same.
I believe this would be something "interactive and appropriate" for their ages as you suggested.
Thanks
T.