Assembling a system over time

I found this forum while searching for advice and components for an off grid system.

The situation;
I work with a mission group in the Dominican Republic. We have purchased a small piece of land which are developing as our base of operations. The power grid is 1/2 to 1 mile from the property over rough terrain. Even if we had the grid within reach, it is unreliable, on only 4-6 hours per day, sometimes off for days at a time. When it is on, it is always under voltage which requires step up transformers to boost voltage for each device(or one large EXPENSIVE transformer). I have not yet even investigated the cost of getting power to our site. I cannot imagine it would cost any less than building our own power system. We get 10 hours of daylight in January, 15 hours in June.

So, we need an off grid power system. Our power needs are not huge, we need to water pump and want to have refrigeration. Lighting is not a big issue, our participants bring LED flashlight and batteries to last them for their stay, AND it is VERY COOL to watch the sky with no lights on!!!!

As with all small mission projects, money is a huge issue and we must use what little we have wisely and SLOWLY. We already own a Honda eu2000 generator we can use to run things initially. However I am trying to develop a plan to develop our power system slowly over time, as funds allow. I want to be sure we do not waste money by purchasing things now that will not be able to be integrated into the system as it grows.

I have calculated our tentative needs, they are no more than 4KWH per day. With this in mind, I am thinking the system should grow in the following manner.

Step 1. Use generator to run refrigeration and water pump. Turn on and off as required to keep things cold and water storage tank filled tank filled.

Step 2. Add batteries and inverter to run appliances and water pump, and use generator only to charge batteries.

Step 3. Add charge controller and solar panels as money becomes available to charge batteries. The generator would them only be used during rare days the sun does sun all day.

This plan may take 1,2,3 or more years to complete, depending on finances and things we learn as the property development moves along.

My initial questions are in regard to choosing a charge controller for now and future. Since we already own the things we need for step one, the next step is to use the generator to charge the batteries. I understand the need for a good MPPT controller when we get to the point we can install solar panels. What I am not clear about is how the generator will eventually interact with the charge controller, solar panels, and batteries. Is there a charge controller that can interface the generator, future panels and the batteries? Or do we just need a good deep cycle battery charger at this time, then add the charge controller when it is time for the panels to be installed.

Thank You,

John