I usually end up buying my party supplies online because I don't always like what available in the party stores. Check around and you can find some decent buys.
I do paper plates from Costco with a 'theme' napkin, then a theme dessert plate with a plain colored napkin. I like to do a theme banner or 1 decoration and then just use solid color steamers or balloons.
Check the
Creative DISigns board for invitations or other images you could print and use to decorate. You could definitely get a name or birthday disign that you could iron on to a shirt!
For cakes, I ALWAYS get my cakes at Costco; they are $16 for a half a sheet and so moist and delicious! For DD's bday I bought an edible cake image on ebay for $10 including shipping (I could look up the name of the seller if you PM me). They can do any image you provide - again this could be customized by someone at the DISign board - or they may already have a Buzz image. When I ordered the cake at Costco I drew a pic on the order form showing that I wanted a colored border and a few small flowers in each corner. The edible cake image is very easy to lay right on top of the cake in the blank center.
HTH!