Which apple watch to get?

Hi, I'm (hoping!) to get an apple watch for Christmas but I'm not sure which one to go for.

I'm not bothered about cellular so GPS is fine - but the two things that I do want to be able to do are:

1). I do a lot of indoor cycling- do all the apple watched track steps while on an indoor bike or only later models? My fitbit doesn't record time on the bike at all.

2). I'd like to be able to listen to my spotify playlists while on a run without taking my phone with me - or do I need to transfer to apple music to enable me to do this?

I'm looking an either a Series 3 or SE.

Thanks in advance!

Julia