what's the ratio like?

anyone has any good coffee bean recommendations/options? prefer:
- dark roast (medium-dark is ok too)
- low/zero acidity
- chocolate/nutty (don't prefer fruity)

tried SOL coffee beans recently (el salvador and sunshine) since it's a popular suggestion in forums and shopee, but i find it has less kick/caffeine than usual, so i'm looking for better options. i understand that better beans are expensive but just checking if you guys have other recommendations with a budget <RM35 for 250g. don't understand why starbucks gets a lot of flak here, i find that their italian roast bean is quite ok 

There are two variants of machine - original and vertuo system. Original line is the older machine. Max is 110ml per cup. I prefer black coffee so this does this trick for me.

Vertuo line is the newer system. Their main selling point is that they can brew coffee up to 500ml per cup.