Getting ready for school

I've been looking at different sites to see what to use in the fall for Kindergarten. Colton will be 5 in June so its time. I think if I stick to only Kindergarten he is going to get bored. Of course there are things he still doesn't know how to do so he can go fully into 1st grade. He still can't write out the alphabet or his numbers. We have just started working on these though. He does however know how to read his alphabet and his numbers. He can even read and spell most 3 letter words and some 4 letter ones. He can count to 100 and can count by 10's to 60. He's working on counting by 2's. He can also count backwards from 20. He can do simple addition, knows all his shapes and even the parallelogram and all his colors. The only thing he can't really do for first grade is write. Does anyone have any suggestions???