Why don't you do this yourself? Go to Half Price Books and pick out several books that you both like. Henry and Mudge, Little Bear, and Nate the Great all have a series of books and they all star boys! Other 1st grade reading books would be the The Tales of Peter Rabbit series, Amelia Bedelia, Madeline, Frog and Toad series, Curious Geoge, Doctor DeSoto, A New Coat for Anna, The Little Engine that Could. The list is endless! Look at the books on his bookself already, no reason he can't read them to you!
Read a few pages every day, and try to build up his "endurance" over a period of weeks - so that he can read longer and longer books over time. If he has trouble with a word try sounding it out, and looking at the pictures to figure it out. If he still doesn't get the word just tell him the word and move on. Steadily pepper his reading with "good job" "I love the way you said that!" "Wow, that was a big word (or long paragraph) and you did it!" Rule of thumb: 4 compliments for every one correction. And be sure to down play any corrections you need to make, "that was a hard word" etc. You get the drift.
Why pay someone to do something he'd rather do with you anyway! Also, this can be a terrific time for the 2 of you to share. My 9 year old LOVES to read to me and be read to. He even demands to sit in my lap for it. And he's a normal kid (he'd die if he knew I'd told anyone that he sits in my lap), but he is still only 9. In a few short years he won't sit in my lap ever again. And neither will yours. :(