Only active product today is System 800xA with the option 800xA for Advant Master. Trending is built-in but cannot service any of the older operator stations.
With older AS500 operator stations still active needing trends, consider installing AdvaInform History option in one of them, or find IMS replacement hardware on eBay, etc. An HP B180L EISA model have outstanding performance and expected lifetime (stay off the more recent B2x00 hardwares). I can also provide description to get IMS 2.0 running on HP B180 PCI model (PU515 RTA). The more recent IMS version AEH 2.x have PCI support from start.
I can see to that you get help from a System 800xA Evolution Specialist with deep knowledge in AC450. Let me know.