XEsclipseD
I wanted to use all my unique but some of them are weaker then the ones I'm using currently in terms...
Ooh I see. Well in that case, you may use the tier 15 helm you currently have. But when you get a level 50 equip uniques like inferno helm then use it, because it has 8 stat options and higher overall stat numbers than a tier 15 armor.
I am in your position once. At first I can't defeat the dragon cause I'm losing life to fire breath and my damage seems just like a scratch off his skin. But by upgrading my armors and accessories, I was able to withstand the damage taken. Use skill or overhead attack before the fire hits you and you will survive.
About uniques in the shop..well you won't get it always. They randomly appear after a draw or some draws. Try a combination of 100 and 10 soul draws if you like.