Hi saundersaw,
Yes, I'm a kite retailer so my goal is normally to encourage you to buy new. I'm going to give you some general advice that I hope makes sense without pushing you to buy new gear.
As a complete beginner without any experience, my strongest advice is to not buy used gear without an expert shopping with you AND coming with you to inspect the gear before forking out the $$. You'll find more tips about what to look for when buying used gear in the article below.
I did that mistake not once but twice as a beginner. Bought used gear without really knowing what to inspect. Turns out the first kite I bought was leaking all over the place and it took countless hours to fix those leaks only to realize there were more leaks and that in the end I should've just replaced all the bladders (This usually cost at least $300 if you do it yourself). The second kite I bought used, the canopy was just so "tired" that the kite ripped in half the first time I crashed it in the water. It wasn't worth repairing it because the canopy was finished.
Safety systems have evolved a lot with regards to bars. It's important that you get a single front line safety system (not sure if that's the case on your Cabrinha bar or not) See article below about safety systems.
If you're on a budget, another advice is to buy used gear from a kite shop. This means the gear has been inspected and the shop will offer you some support in case something is wrong with the gear. You will typically pay a bit more when buying used gear from a shop vs the online ads but at least you'll have peace of mind knowing that 1) it's the right gear for you and 2) it's in good working order.
I would not recommend buying kites this old (2012). Back then all valves were glued on the bladder regardless of the brand, which means that over time they will eventually ALL peel off. Even if the kite hasn't been used much. Australia is one of the worst placed to be for these old valves (heat, sun). Changing all the valves or replacing the bladder will cost you more than the kite is worth. Post 2016 kites almost all have HF welded valves which means that the valves are welded on the bladder instead of glued. In other words, they can't come undone.
As far as sizing, you forgot to mention where you are and what's the average wind speed during your kite season (see article below)
If you stick to this sport, you'll eventually realize that it's not a budget sport and that if you want good gear that performs well, you'll have to spend more than you thought at first.
Some more reading you might find useful:
www.kitebud.com.au/kitesurfing-online-courses/kitesurfing-safety-systems/www.kitebud.com.au/6-things-to-look-at-when-buying-a-used-kite/ www.kitebud.com.au/how-to-choose-a-kite-size/Hope this helps,
Christian