It looks as if you have room on the back of the seat pedestals to put in the burner and sink as shown. I would first find a sink which will fit in the area. See how much room is below it--to get a good drain overboard--and keep the thru hull above the water line. You may also want to measure how much room is available for the water tank. There is a very small 12 volt pump, by Jabsco which fits in line, and then you don't have the issue of putting in a manual pump--which will be problematic for your layout.
If you want manual, then a Whale foot activated pump may be best. These can be cabinet or floor mounted.
We have a larger NuWave induction burner, which we can run off the Honda EU 1000 (at "medium" setting). The small induction which Marco has also uses 1200 watts, but should work at the low setting. (or an an inviter).
We have an aversion to the propane or butane (butane vaporization pressure is such that it has to be warmed in cold weather--propane is better for that), because of the danger of fire and explosion--not personal experience, by my best friend spent over 3 months in a burn unit due to those bad "seals"--with 30% 3rd degree body burn. We do carry propane single burner, as a back up--and it is only used out of doors.
If you are using lubricants on fuel "O" rings, be sure that the material is comparable with that "O" ring material. Petroleum products are generally not recommended for rubber. Special silicone oil and greases are recommended.
Parker and several other companies make specific lubricants.
If I was only occasionally using the stove, the small induction would be very tempting--with a small PSW inverter 1200 watts, or even 800 watts and keep the burner on medium, which is plenty to cook most items and boil water for coffee.