If you like full milk, you can do full milk along with the coconut water.
To find out what full milk is for your batch, add up all the water amounts (from your aloe juice and your coconut milk). You'll get a number of x grams of liquid. Then consult the tin/reconsitituting instructions for the GM powder to calculate how much milk powder you need to get x grams of liquid GM. You may need to use a bit less GM powder since not all of the weight in your liquids is actually water (might be bits of coconut and aloe).
As an example, my GM powder tin says: "Mix 25g GM powder with 190ml of water for 200ml of goat's milk". 1ml water weighs 1g, so you'd use 25g powder to 190g water. If you were using plain water, and your water is 316g, you would divide that by 190 to get 1.66. Multiply 25g by 1.66 to get ~41g, the amount of GM powder you should use. Note that the instructions could be different on your GM tin.
Now, the above example is for pure water. If you've got other goodies, you could do some research into how much of your planned amount of aloe juice and coconut milk is actually pure water, sum them, and plug that into the calculation above. In practice, though, it's mostly ok if you eyeball the amount of goat milk powder to subtract from your final amount to make up for some of the weight in your liquids not actually being water.
Just to help you with your worries, I've used waaaay too much GM powder before on a soap. Like almost 2x more than needed to make full milk. I used a 40% lye solution and dumped all the powder in the oil. The only result was that it ended up with a sickly sweet smell, and its superfat was higher than I planned. I didn't fragrance it, but if I had it would have been pretty good to use. I think it was fine because my goat milk was pure and had no other additives. If your GM has additives like lecithin, I would make sure it was fully dissolved in liquid before stick-blending it into the oils to ensure it's well-mixed, because lecithin can sometimes cause separation in soap if it's not dispersed properly.
Full milk should be just fine for you, and you can use less than that if you like. Along with CM the GM will increase your superfat a tad and make your soap softer initially, but if it does it will harden, especially seeing you have a good amount of lard in there.
