I was thinking of making this recipe but my homebrew store doesn't have any Northwestern Gold LME.
Would any old light malt extract be an okay replacement? A full list of (liquid) malt extracts I can buy is here.
Based on Northwestern's website (http://www.northwesternextract.com/brewing/malt/), their Gold LME is equivalent to light LME (not extra light) from other companies. It falls right in between their Extra Light and Amber LMEs.
Based on this Home Brew Talk thread (http://www.homebrewtalk.com/f12/what-gold-lme-126714/), the last post explains that Briess also has a Gold LME and what's used to make it. I would guess that's very similar to Northwestern's.