There isn't an armor shop in Size Matters, you need to find the every piece of armor in the game on your own, and equip them in order to use them. here is a list of all the standard armor sets in the game, each set has 4 pieces to collect.
there is no armor shop just type in armor combonations.
if you go to game.co.uk and search ratchet and clank a crack in time you will find 2 the normal one[£39.99] and the collectors edition[£49.99] or go to the shop and ask. i dont think this would help if you live in the US
Off the ps3 shop channel it's about $15.99 in store it's about $35.99.
it is a rare armor it can be purchased from quibble's shop
in yulgars shop
Upgrade shop
Find an armor shop that has rune armor or buy it at the Grand Exchange in Varrock.
The Suggestion Shop, although most of the armor cost ACs.
During the first playthrugh of the game, I believe the most powerful armor you get is the Fire-Bomb armor. During the second playthrough, you get the Hyperborean/Ice II armor. And in the THIRD playthrough... You get the Chameleon armor. Also, here's a tip for you. Once you get all the Chameleon, Wildfire, & Sludge Mk. 9 armor, pair them up like this: Wildfire Helmet Chameleon Body Armor Sludge Mk.9 Gloves Chameleon Boots This gives you the stalker armor, my personal favorite. Just thought you'd like to know.
You get it in the Girly shop in tercussinotlim or whatever
from harvest festival shop
Crimson Paladin Armor