How do I know what career Is best (of the 2..)?

The money is in the technology. Unless you get a Masters or PhD in Astronomy and have some ground-breaking ideas and techniques, it is unlikely you could make a living at "Astronomy". Go with the tech route and keep studying Astronomy. Maybe there will be a way to combine the two. Keep in touch with the local organizations (like a large telescope) around the country to see if they need people with your skills. If you love something, start on the ground floor and work your way up. Even if it's only data entry of sightings at the observatory. You'll get there.