Anti-Staining Bodysuit

Resin isn't as stain-prone as vinyl, and I'd say a stain-prevention suit will mostly be unnecessary unless you plan on dressing your doll into dark, unwashed and unlined clothing that you plan on leaving on for a prolonged period. If the doll's body is body-blushed or sprayed with sealant, it might stain a bit more easily, but not to the extent as vinyl does. Washing dark clothes prior to putting them on is usually enough for resin dolls.

That aside - you'll have to compare the body measurements, but the volks MDD size bodysuit could fit SDC. I've also seen different sizes from various makers on sale on taobao, etsy and ebay, and coolcat has a wide array of body suits.