Just to clarify, are you referring to Cisco Data Center Unified Computing Sales Specialist? If so, please visit the Unified Computing Technology Specialization page for information on recommended training.
For Cisco R&S Sales Specialist, you can visit the Routing and Switching Specialization page. However, the R&S specialization was retired and you can find additional details in the Partner Program Announcement. For specific questions regarding the specialization and possible available replacements, please consult your partner account manager or you can open a case with Customer Service Central.
Cisco Learning Network Moderator