So, I bought the 1.25 iso plate, what else will I need to have a complete keyboard?
Case, USB cable & keycaps right?
Where can I get those, also I'd like to buy blank keycaps, do I need to look at anything in order to make sure I get some that match my switches?
There are a couple community designed cases in the works, including metal and acrylic cases, and sometimes a Poker or Pure case pops up in the classifieds.
For USB cables, Paranoid and Pexon are EU/UK based and TJCaustin (Mimic cables) and I are U.S. based. I can ship to Europe and I believe TJ will as well.
Blank key caps can be gotten from many places with for standard layout. Check out WASDkeyboards if you want something super cheap, there's some stuff on eBay, there's Signature Plastics, there are group buys, you have people like Feng who have their own webstores, and, if you're feeling adventurous, you can check out Taobao.