If you're talking about Estoril, that was a garage kit, as in a resin kit made by fans to be sold at specific events in Japan and only at those events. Unless you have a load of cash and a middleman or forwarding service who does bids on second hand auction sites like Yahoo Japan Auction, as well as a lot of luck since there's never any guarantee these kits will ever show up on YJA, you're not going to be able to buy it.
As with all fan-made things, no, there is no checklist or anything like that. Or at least nothing that's complete enough to really qualify as being a checklist. Best thing you could do is follow the people who make the specific kits you want and see what shows they're going to, wait for them to post information on what they're making for said show, and go to the show yourself and buy it.
If you're talking about the new Arnval and Strarf plastic models that are going to be produced by Kotobukiya but are currently seemingly stalled with no release date announced yet, then I think I just gave you enough information in this very sentence to go look up stuff on the products yourself.