I can't speak to the oscmax thing, but there aren't any hidden costs involved with Zencart.
The Book is excellent for understanding, installing and configuring Zencart, but be aware it contains almost nothing about styling and templates.
1. Search the Free Software Add Ons for 'attributes image' - there are a couple that seem to do what you want. Test them on a non-live test site first.
2. That particular look would be pretty easy to create in Zencart. An experienced Zenner could have it looking close to that in a few hours.






