Hi there! Full disclosure, I work here, but we over at ShipMonk have a facility in Redlands, California (SoCal). We absolutely integrate with Shopify. Check us out -- we might be what you're looking for!
Leon here from Shopify Support.
What kind of products are you looking to sell? If you leave a bit more detail on the product category you're looking to sell in your store, the suppliers who browse through or find this post from search results will be more likely to respond and offer services.
All the best!