Create some visuals for printing on T-Shirts

I need a fast creative designer to help us visualise some designs to include our logo on to some T-Shirts we are planning to purchase for a trip to Romania. You should have software that can show the designs on a T-Shirt. The designs we need are very simple utilizing our existing logo which is in 2 colours and single colour text on front and back of the T-Shirts. Our existing logo may need some amending or re-drawing but nothing complicated would be involved. You will have experience in creating attractive designs with good use of font style and an eye for colour combinations. We also hope you can work with us long-term. We are considering yellow T-shirts with one or 2 colour prints and red t-shirts with one or two colour prints with our logo adapted to suit screen printing.