Not sure but I think Goldstandards has the larger base set, so it would be more difficult since even base is numbered. Maybe Black will be slightly easier/cheaper but Gold probably look a bit nicer.
Definately gold standard, bigger base set, better challenge and great looking base cards. Would look great all-together. Given the prices many of the inserts go for as well, you could even chase the insert sets.
Is that even a question? Black Elite is down there with Donruss with the crap and value they've been putting out. Gold Standard on the other hand, has been one of the best Panini releases this year :v: