Design Kit (tee-shirts and hoodies) for Junior Triathlon Club

Hi, we are a small junior Triathlon Club (www.turbokids.co.uk) looking to get some tee-shirts and hoodies designed and printed for the autumn/ winter training season. We already have one tee-shirt designed (please see attached) but we would like to make it a bit more fun to appeal to our young members. We need a unisex design as we have an equal mix of boys and girls in our club.
For the hoodies, we would also like a fun design with our club logo and/or name on 1 sleeve/ front and back. Maybe a combination of print and embroidery. As a not-for-profit club, we have a limited budget.

We are looking for a UK based apparel designer who will come up with a simple, fun and bold design for our club tee-shirts and hoodies at a reasonable cost. We want to stand out! If you are able to recommend a good printer (Uk based) that would be appreciated.

We will produce around 12 of each initially so we try to keep the design fees reasonable to keep the club kit affordable to all club members.