Chosen Solution

I want to have 2 storage devices, in other words.

Here’s the guide for installing an SSD 2.5” drive. Installing iMac Intel 21.5" EMC 2428 Dual Drive Kit You can then use the optical bay for an additional standard drive. @danj shows how to do that here: Configuring a dual drive setup

Hi David Technically it is possible, one way is to sacrifice your optical drive and get a optical drive to sata bracket converter to fit your sata drive.