Structure does not and cannot exist in a Quark-Gluon Plasma. Thats why it (the QGP) exists. The kinetic energy (i.e. thermal) of the constituent particles (quarks and gluons) is such that they overcome all attractive forces and just start bouncing around like mad. Normal matter does not exist at these temperatures, nor could any sort of order be maintained. Period.
As soon as the QGP cooled to below its threshold temperature (a few trillion k) it instantly reforms into hadrons. Seperate hadrons. Then EM and Gravity take over, the strong force does not work between hadrons. So, no Uso, they would not cool into a proper arrangement. It would go from the total chaos of quarks and gluons zipping about to the chaos of random hadrons zipping about.
I stress again order could not be created in a QGP.
Metals reform into crystal lattices because of the formation of covalent bonds with there valence electrons. The electromagnetic force (or gravity) does not play a signifigant role in activity on the quark-gluon scale, the strong force does. And the strong force (with the random bonds being constantly formed) would end up not allowing a structure to form. Further, the weak nuclear force would cause any large hadron (note that mesons are hadrons too) to decay into other smaller hadrons in very, very s hort order.
No particle could stop this.