I need to get some plates, initially for my Adjusted Pixie, but hopefully that will still be useful when I manage to get Viceroy (I am farming mats for it myself). I am unsure of which all round plates would be the best bet (I know it depends which mob you intend to hunt)! Also, I am not sure where to pick these up? There are only 5A's on auction on Ark and I cant find any at booths/ shops etc. Any help would be much appreciated.
I believe Kikki Jikki Defense and .Point Shop in Celeste Harbour North both carry a good array of plates.
I do like the pulsar 8 plates but they are L. My recommendation is take a trip to Caly just to buy a set of 5b plates. Auktuma usually has some in a shop keeper in an apartment at Genesis Amethera building B i think it is (it's the one just east off the TP) floor 7 apt b or c. Good luck in your search.
You currently got Adj. Pixie and you are working on getting Viceroy armor, good going! I just want to let you know that there is a ton to hunt on Arkadia (and also Calypso) with those two armor sets where you don't need any armor plates. I don't know your stats, but if you go and buy plates for armor you might end up hunting far above your level and lose out more than you bargained for.