JetAudio definitely supports SMB; unsure if it uses jpg art but there's a free version to test with.

JetAudio definitely supports SMB; From the app store page:

It can stream music from shared folders on local home network or WebDAV servers. It works with shared folders from Windows, USB drive attached to router, Network drives (NAS) or WebDAV servers.

Unsure whether it supports jpg album art, but there's a free version to test with.