beginner

main purpose is to make music on the internet, techno, orchestroal, etc

Depends on how much money you're willing to spend. Are you thinking of Yamaha only? I ask this because your question is in the Yamaha section.

I don't know much at all about the PSR arrangers. Maybe one of those will be perfect for you.

You could start with deciding how many keys you'll need. 61? 76? 88?

Can you be more specific as to how your music will be presented?

Best wishes
<><
Bob

Yamaha DJX

For your styles mentioned, I'd consider the following pirced from cheapest to most expensive:

Yamaha DJX
Yamaha CSX 6
Yamaha PSR 2000
Yamaha S90
Yamaha Motif

The Motif ES is coming out in October. If you need a workstation, this would be a great option and your most expensive option.

Don't let some sales person wow you in a store. They will purposely set up specific keyboards to sound great. Usually the ones they need to unload. Listen for yourself. My friend just got duped into buying a Roland Fantom S because of this tactic.