He copied his style from a Laguna cosplayer?

Laguna's style and Seifer's are similar, but Gunblade training is part of basic training, dweller. That's where both of their styles originate from. Squall's style does not resemble Seifer's, however.

Not sure where the hell you're getting that Dollet's nautilus store is where they got their equipment, instead of, you know, the mercenary military academy they spent a good ten years of their life in.