@rverma, I'll add a few bits on having the same regs across all tanks.
My OCD likes that approach, too. However, from the operational perspective, I like having 2 different reg sets that I can easily identify. If there is a problem with one manufacturer and you have all the regs from that maker, you're out of luck - need to pay attention to all the regs. If you split your regs across 2 manufacturers, only half of your regs will require service. Also, when I have two separate reg sets, I can easily rotate them - one set on the bench, one in flight. Being able to repair two diff makes is also a plus. In my case it is Deep6 (diaphragm) and MK10 (piston). This is probably splitting hair for some folks, but I find it comforting ;-)
I cannot comment on mk19/g260, but Deep6 breathes just as well as mk10/g250 - which is probably one of the best combos. Deep6 advantage is the service and support you get directly from the corporate. Several people on this board are Deep6 management. For us in the US, supporting Deep6 is also a part of the pride. As you're North of the border, you may not have the same feeling.
Finally, if your Apeks are fine, why sell them? You can keep them and get another reg set. Again, my OCD feels you, but I try to fight it as hard as I can. Let's not waste $.