How do i tell my friend i am hiring a different vendor?

A good friend who my fiance and I go to church with who is a hair stylist and also does my hair offered to do my hair for our wedding and we had a conversation back in August how much my deposit would be and my trial. We agreed upon $100 deposit and $100 for my trial and that was going to be his gift to me. My wedding is in May and I have been trying to get my trial on the schedule with him since September and he just seems very busy like he has too much on his plate and I've been getting the run around. Every time I bring up scheduling my trial he says he will check his schedule and let me know by the end of the day but unfortunately falls through. Today I told him I needed to book my hair trial because my makeup artist is booking up fast due to wedding season for spring and I gave him two different dates in March he told me he would definitely be able to do either of the two dates and would confirm and let me know by the end of the day. I don't know how to tell him I will be pursuing a different artist without hurting his feelings or causing any harsh feelings. We also go to church together and have a close relationship and spend a lot of time serving in the music ministry together. I have found another vendor that is more flexible in her time and I enjoy her work that she has shared with me and she is very responsive that I would like to pursue instead. She has availability next month for a trial and I don't know if I should wait around on my friend or go ahead and book the new hair and makeup artist I found who specializes in wedding events.