Transitioning to Chapter Books for Reluctant Reader

My 7 YO ds is a very reluctant reader.  He actually reads very well, but doesn’t think he does.  If he comes to one word on a page that he doesn’t just know, he wants to stop reading the entire book.  His personality is that he is very hard on himself.  We encourage, read with him, etc., and it has gotten better.  I will “catch” him reading on his own sometimes but not very often.  He does love me to read to him, so he enjoys books just not on his own too much.

OTOH, my 6 YO ds is an avid reader, but tends to stick with picture books.  He is a very strong reader and enjoys reading.

Dh suggests that we do a reading rewards program in our family this summer to encourage them both onto chapter books and also hopefully get my 7yo to enjoy reading more.

I would like to make a list of books for them to pick from and would love some suggestions on some especially for my 7yo who is reluctant.  I want to set him up for success with this.  We own lots of books and have a library literally across the street, but it overwhelms them.  I think a list to pick from will be better.

He has enjoyed the Nate the Great series (I know they are twaddly), loves Little Bear and Frog & Toad (though these are really too easy for him), but doesn’t like Billy and Blaze for some reason.  I’m hoping to show him he can read things like The Mouse and the Motorcyle, Hank the Cowdog, Boxcar Children, etc.

What books or series would you suggest at this level as we try to encourage this transition?  I’m also thinking he might do better if I have him read me a chapter a day (or a few pages) instead of just handing him a book and saying go read.  Any other suggestions are welcome?  I have always loved reading and it makes me sad when he says he doesn’t like it.