Searching for a T-Shirt Designer with huge experience

I'm searching for a T-Shirt Designer, which is able to create 5-10 designs minimum per day. You also should have experience in T-Shirt biz and be able to search for profitable niches for T-Shirt Designs on your own. Previously I had a lot of issues because of bad english skills, so your english texts should be grammatically correct. I need 4000 x 4000 pixel and 300 ppi designs. Designs should be for commercial use and designed by your own only for me, without Copyright issues. I'm searching for a full-time designer who only works for me. If you really want this job, please do some research for a profitable niche and send me some designs as samples. Designs should always be created for black shirts, so use bright colors for the texts. I'll pick the best of you and give him the job! Payment will be with Paypal weekly or monthly per unit.