1. The Artmolds pressure pot uses the design that screws down into the lid, which will eventually lead to failure over time. I recommend you stay away from pots with these designs. I started with one myself, and it immediately had issues. Plus, 40 PSI doesn't give you a lot of headroom.
2. I own several CA Technologies pots, and they're great. They use a totally different method of securing the lid to the pot, specifically one that won't get you killed. The pots are very sturdy. The next step up would be Binks, but in terms of price/performance, I think CA Technologies is great. Finish Systems is a great company and they ship quickly.
Here's how the whole vacuum vs pressure thing works: Both are really essential, but if you could pick only one, I would choose a pressure pot first, and then get vacuum later. Vacuum is really great for getting the bubbles out of thick silicone, but if you're just starting, you're going to see more results from a pressure setup.
If you're also looking into vacuum setups, take a look at bestvaluevacs.com. They're helpful over there and can point you in the right direction.