Gelatin is great! Just add your decarbed concentrate to the gelatin/jello portion of the recipe. Infused coconut oil counts as a concentrate and will work fine (tincture or non infused concentrate is what's typically used and mixes a bit better).
Gelatin works as an emulsifier, you can add MCT oil but it's not needed as an emulsifier, imo.
How many pieces the dish eventually gets divided into, and how heavy the dose you want per piece, will determine the amount of concentrate to use. If you take 1 ml of the infused cannabis now as a dose, then I'd calculate how many pieces you're going to cut the final dish into, and then add the appropriate amount of concentrate to accommodate that. If you poured into a 15 mold station, and you normally eat 1ml of oil for a dose then I'd add 15ml of coconut oil to the recipe, so each individual mold/piece would be containing 1ml of infused coconut oil.
Here's another quick link.. Mmmm (wine + THC) gummies...
https://gethighlikealady.com/new-blog/diy-marijuana-gummies