Hi, my son is 7 now and we found out he was diabetic at 5. The first year we talked about pumps and he was not ready, not even a little bit. We looked at them and he liked the colors, but just not ready for another change. We let him be ready first. We did talk about it alot, but what the seller for him was.... we went ta a walk for a cure meeting, this being the first time he played with other diabetic children. He then was drawn to a kid who he thought was pretty cool. he had a pump and showed Ethan and he then saw how easy it was how much quicker his new friend was eating and then done so he could play. He looks for ways to be "like everyone else" and this gave him a closer opertunity.
My son did kindergarden on shots. The key is to find a very good support team. Spend time with the staff until you are comfortable. Shots are harder on the staff, but if they are easier on your son , I say..... he has enough hard stuff, someone else can handle a little if it makes him happy. If he truely does not want the pump, he will be o.k. during school with shots. Set in place your 504 plan so it is very clear expectations. do not allow them to lock up his supplies, and find out what is the emergency plan. School fire, bad weather kind of thing. Who will be responsible for his supplies? What will they do in the event of a diabetic emergency/ Ask them to do a drill. they practice fire and stuff like that.
I do not know that you will be able to convince him it is best. See if there is anyone in your area who is on a pump. Hopefully his age or a little older. Generally families would be very helpful to you.
My little guy is even able to eat school lunch. A good support team is what makes diabetes at school easier. That is with shots and pumps. Hope this helps. Good luck.