I never seen split kitchen Recepticals. I imagine the electriction was making it so you could use 2 appliances with a big load in the same receptical at the same time. Because it was 2 circuits on the same yoke it should have been a double Pole breaker.
You are fine just putting one circuit for half the kitchen GFI's. These can be single pole breakers (20 amp with #12 wire).
No main disconect would be acceptable if is with the meter. There is also an exception if the panel does not have more than 6 breakers.
Pricing of electrical products around here reflect demand not what's included. A panel without a main is almost the same or more than one with. But if you need the just main breaker and any hardware you might be better off buying the whole panel.
Tom
