I have an application just like Sai, but with not as many brushes. I was very puzzled at first. But then I got the complete hang of it, making my first textured preset in under an hour. My preset is in my signature and avatar. But do beware, when you do the mane, it will appear glitchy and the textures will be sticking out. So just when you get to that part, the mane, check out Ruby1234's topic in Member Made Tutorials ;)
And if making a preset, you will have to load the UV file, found in FeralHeart>My_presets>Reference. If it is not loaded, your character will appear yellow and black.
If more help is needed just ask ;D
Making a preset is easy and fun :D