I have a couple Spidey suits from printcostume that are pretty good quality for the money, they offer custom sizing and all the kinds of zippers you might want too.
For singlets WrestlingMart has been pretty good for me, many different brands to choose from.
Underwear has been a bit difficult for me, tried many brands over the past few years, but I did just get a few pairs from the brand Awry, they have been very nice, and some from the brand Krakatoa, also very nice (love the front fly briefs they have🥰)
Hope this helps!!😸