The best gear you can make is actually made ingame.
Thankfully grand fantasia gives players the choice to spend or work hard ingame.
Although you cannot directly 'craft' the gear you can buy in the item mall, you can typically buy it from the Auction House. Thankfully enough players use the Auction House for there to be items you need to be in there.
FYI the only 'gear' you can get from the item mall is a thing called 'legacy armor' a blue-colour armor with stats beneficial to people who are typically leveling : movement speed, combat experience and item drop rate. However by any means it is not neccesary to get any where in the game. You can even get lucky and get this legacy through using a 'lottery' type item called 'Magic Alchemy Clay' that you can buy from the auction house or get from the item mall.
I recommend that you try to use Magic Alchemy clay at-least twice a week or however often as you like as you tend to get lucky sooner or later. Between the 8 clay I've bought and used I've won : Laserblade, Templar Legacy, Assasin legacy and two Crystal chisels (I think has brought me really close to getting an SKB4). I know that it was a risk but use only one or two at a time and wait a week between uses.