Global XP Ships

I just realized I have 760k gxp and need advice on wether to get a Tier VII or save up for a Tier VIII or possibly even Stalingrad.

Keep in my I already own most of the GXP except the german BBs. The ones I own already that are available for GXP: Massachusetts, Azuma, Suzuya, Atago, Monarch, ZF-6, Flandre, Republique, Champagne, Gasconge, P. Bagration, Roma and Friesland