If you already own vSphere, there are promo's and SKUs for upgrading you to vSphere with SOM, which is vC Ops STD. However, that may not be a good choice for you if you'd already in-flight on a license or want a higher tier vC Ops edition. If you want vC Ops Adv or Ent, you'd need to buy a vCloud Suite or the vC Ops Suite (vROps). If you own vCloud Suite, you get entitled to vC Ops in one form or another depending on the level of vCloud Suite you own.
Hit this link for the vC Ops Suite:
vRealize Operations Intelligent Operations Management: VMware | United States