Design a Logo, Design Tshirt Logo, Design Hat Logo

I am launching a new business to celebrate autism and parenting children with autism. I'm putting a positive spin on something which is typically treated as a tragedy. I am looking for a designer to help me create a logo, custom font, imagery for a website as well as apparel. I will be uploading the designs to have them printed by other people so the designs need to be scalable and easy to use by tshirt printers for the various sizes. At this point it will be 4 Tshirt/Hat designs with different slogans. I need to own the designs and the font outright (alternatively if you can help me find a common font that I think is right that would be even better) The font would have to have the ability to be duplicated by another graphic artist in case I have to use someone else down the road. I would, however, like to create a long term relationship with a designer as my plan is to introduce new designs periodically. I would like to continue to use the same person going forward. I will need some imagery in the designs as well - centering around the idea of a spectrum. I'm thinking something like a prism with colours emanating from it . I would also like to use the idea of the dark blue puzzle piece which is common imagery for autism, perhaps with something associated with a spectrum incorporated into it. The general feel is of fun and needs to be appropriate for both adults and kids. Thanks, Sarah