base lg armors are located in faar(strigi/regulus) and andol(opal/deatheater). need to decide which you want to use till rdy to morph to a diff non store sold piece which have better % for procs. to morph an lg you need the lg armor, 100 heroic ess (must be full stack so need least 95 stacking skill) bought from ah or farmed in hero mode. then you need an armor ess for the type of armor you wish to morph to which is bought from ah or use t30 cloth/dust to have a random one made from another player. when all items gathered take enchanting rod place the armor ess in top left slot, actual armor peice in top right slot, then hero ess in second left spot under the armor ess, hit submit and you have a new lg armor.
also if you are going to morph right away then strigi is the cheapest armor to buy from store, also cheapest to uptier which is best to do before you morph if interested at all. a few players also craft certian lg armors so can buy them from ah or straight from players like raiden peices. lg weps are drop from lg beast only, one's that have dropped are crafted to produce more, must be bought from ah/player or kill a legendary beast. lg shields is same process as armor, only diff is instead of a cloth/dust to make the armor ess you need cloth/scale(i think) t30's.