The problem is I don't know enough to know what it is I want hence this thread. As for the DM candidate...I still don't know how that is there but apprently it is quite the big deal as I have multiple people question me on it.
Well, you should know this:
If you progress all the way up to Instructor, in sport diving (aka what many people mean when they say "recreational" diving - versus technical diving, which is still actually recreational diving*), you will still not be diving with Trimix.
To be using Trimix, you would have to progress from your OW sport diving certification into a tech diving curriculum, which is a completely different thing from sport diving Instructor training. Well, unless you get into one of the less-common agencies that teaches Recreational Trimix, but I digress...
So, if you're just going for OW Instructor, you'll still only be diving air or Nitrox - not Trimix. And if that changes your computer requirements to remove the "Trimix-capable" requirement, then you have a much bigger store to shop in.
*Recreational diving includes sport diving and technical diving. Other types of diving besides "Recreational" are Scientific, Commercial, Military, and Public Safety (that I can think of). But, usually when people around here say recreational they really mean sport diving - which is generally defined as one gas, no overheads (e.g. no going inside caves or wrecks), no decompression, and a max of 132' of depth.