You may struggle to find someone willing to give you one or sell you one.
I think the forum was set up to help people make their own tunes
Invest in a cheap dumb FTDI KKL cable, download Nefmoto flasher, ME7Sum for checksum correction and get reading the s4 tuning wiki. I'm still a massive noob.
Read the wiki, pick things up and if you're unsure ask questions on the forum. There's plenty of really helpful guys on here who will give you sound advice.