Changing the regulator configuration

I am at a point at which I don't know anymore what I want/what makes more sense.
Hope you have some ideas.

now:
Mares MR22 DIN 300
Mares: Abyss (2005 model)
Octopus: Mares Rebel
no pressure gauge, but computer with sender.

I don't like the Mares Rebel want to replace it.
I have a pressure gauge
I got a second MR22 (but DIN 200)
I got a Abyss (the model before 2005)
My BCD can do singles only

I stay in Thailand and have every time a new buddy and want to be as self sufficient as possible.

What to do:

a) Remove the Mares Rebel, add the pressure gauge to the second MR22 and go with 2 first stages, 2 second stages. I like that idea, but never seen two valves on a tank in Thailand. So I can't do that, or????

b) Remove the Mares Rebel and add the second Abyss as Octopus. But hose would be too short and the MR22 has one special LP port for the Abyss which is bigger...I would some kind of adaptor or different hose...So I am not sure how to do that and second I would have a useless first stage.

Any other idea??

1. Put the second Abyss second stage on your primary regulator as an Octo. It ought to work on the original octo hose (longer length). Innovative Scuba and Trident have various hose adapters that should be able to fix any compatibility issues with hoses. You might want to detune the octo a tad to keep it from free-flowing.

2. Take the SPG off the second reg and put it on the other HP port on your main reg. It will provide redundancy to your hoseless computer. That way you won't lose a dive if your computer won't communicate with its transmitter.

3. Hang on to the extra first stage and make it a spare. It can be a source for parts should you ever need them. If not, it can be a cool paperweight.

4. As an alternative, you could find an H-valve for your tank(s) and hang the second reg along with the original octo on one side of it. It will provide almost total redundancy for your primary reg, limited by the air in the tank. H-valves are relatively rare, but they're out there. Trident and Innovative would be good places to start looking.

Yup, in a nutshell, leave the hoses where they are and just swap the 2nd stage bodies. The 1/2 fitting is only on the 1st stage side. The reg hoses are the same on the second stage side. You won't need any adapters.

that are good news....
I thought also the fitting on the second stage is different.
so i just swap the regulator....hope that it does not need adjustment and have a nice octopus.
Thanks