We buy pajamas every year for our family..not matching...just a fun new set. Santa leaves them on the porch in one big wrapped box on Christmas Eve. It is a fun tradition and we all have fun seeing what everyone got. It helps them settle in for the long night.
I always buy from Gap or Old Navy. You can go online and buy from both companies and pay once..they are all on the same website...along with a couple other companies.
This year we are stepping things up and we all get slippers too! The kids are gonna go berserk when they see that wrapped package on the back porch.
Good luck and best wishes at finding a fun pair of pj's for your boy!!