Can't help you with the merchant part, but as for items... stuff for SP3 are lacking.... character addons, clothing textures, new clothing items, hair and hair textures. V3 is great, but she's way over done and has way more pretty things than SP3 does.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi