The best thing you can do is to start right here with the Beginner's Guide
. Among other things you'll find in that guide is the recommendation to buy a bass from a real bass bass shop. The basses you mentioned look like house-branded Chinese and European imports of unknown (to me, anyway) quality.
You are wise to be planning on getting a teacher. Besides teaching you proper habits and technique, a good teacher will help you to prevent injury-- which is likely more probable than you think.
If you're not sure you want to take the plunge, renting is a good option. Its important, though, that you rent a quality instrument that is properly set up. Nothing will discourage you faster than an instrument that fights you all the way.