Hello DQ1, best wishes to you as you work on your playing card project. As you already discovered,
Shuffled Ink is great for prototypes, and I'm glad that worked for you. I've personally found their service good as well.
Going with
LPCC for the larger print run is not a bad move. But LPCC's Stud Finish was a very limited stock and to my knowledge is not available to customers anymore. It's almost too soft to be practical anyway. You should also know that instead of printing mostly in Taiwan as they did previously, LPCC and EPCC are now operating primarily out of a new factory in China that they are partnering with. You can read full details in
the article you linked to, including about their Viper Finish and their Crushed Classic Stock, which are their two most popular ones. I don't know that printing outside the US is going to increase your fulfilment costs significantly, because manufacturers operating from China and Taiwan seem to have good channels in place to make their final prices a very competitive alternative to going with USPCC in the USA.
If you want card quality that is almost on par with USPCC, another option you should look into is
WJPC. It is also based in China, but their German 300gsm card stock has been receiving very positive reviews, and most people consider its quality and handling close to being on the level of USPCC's crushed stock. Personally I've been very impressed with the durability and handling quality of this particular stock, and so have a lot of people. For an overview of this particular manufacturer, see my article
Playing Card Manufacturer: Shenzhen Wangjing Printing Company. WJPC has been used successfully by big name designers like Stockholm17 and others, and is making an increasingly positive and substantial contribution to the playing card industry.