PM 107barney YT member here, she can make great clothes. There are some others here too but that is the only one I have used so far.
Washable and reusable dog and puppy pee pads, belly bands, and diapers at T. Bumpkins & Co. Web site.
Even if you just had one pair of PJ's for now till he gets a little bigger.
Also not sure if you have a Ross, sometimes you can find clothes there. Its really hard to find that size in the stores.