You can also use BG gears as an alternative if you dont want to buy GT.You can get them from a nadir seller after completing CL. The stat difference is small , the only real difference is in defense.
For example, GT vestment gives 18 magic while BG gives 15, as you can see 3 magic difference. Its not much difference.
I use garnet signet because it gives 2% accuracy and 16 magic.
and Inward power amulet.