I would suggest you follow up and at least check it out. You are correct in that you can have some influence on their sound or choice of music. You looked up a definition of "stoner rock" - it may not match their definition.

As far as equipment goes, can you rent amps in Denmark? If so, maybe you could do that until you can buy your own.

Also check out what you can get going with fellow students at the music school. Don't put all of your eggs in one basket and keep you options open. Play the field as they say.

Unlike dating, you can be invovled in multiple bands :-). I know plenty of people that are in more than one band. One may pay the bills (wedding band) and the other may be for personal tastes playing music they personally like or wrote.