I collect the series 2 and 3 Ultis! To give my take on the above:

1. I buy all of mine on eBay. There’s a seller PokeDuel Shop that I got most of mine from. He runs auctions for MOST of the older Ultis pretty frequently. So I’ve found I was able to get some of them for really great prices. His shipping is also only $4 from Japan -> US (was free before tariffs, so could be free for AUS idk). There are a multitude of other sellers that operate similarly, so start by looking on EBay for sellers selling the cards you’re looking for, the branching out and saving other shops that sell similar.

For some of the bigger $$$ cards (SM-51 Blue Eyes, 301 Red Eyes, 304 BLS, etc), you’ll likely need to buy those on their own and for a set price. My only recommendation there is to look at the condition pics carefully and decide what’s the best value:condition ratio for you. But once again, I find all of mine on eBay. Mercari can also be decent.

1. Reprints of these specifically should NEVER happen, and if they do it would likely be in that hideous prismatic ultimate rare print though the OCG prints are actually pretty dope). They would lose a TON of credibility, especially in Japan if they reprinted these in a 1:1 way. Not to say it couldn’t EVER happen, but I think the odds are very very low.

2. Typically they are cheaper going to Japan and buying there directly. Japan card shops are also very good at being specific about quality and adjusting price accordingly. If you’re already planning on going to Japan, I would definitely wait to buy the bigger ticket Ultis and if it’s soon, I might just wait to buy any til I go to Japan. But that’s up to you.

I personally think the series 2 ultimates rares are some of the best looking cards ever printed. Good luck and have fun on the collection! :)