International Manufacturer Wants to Start with an Audit; Go From There

We manufacture stainless steel wire ropes and fittings for architectural railings, safety systems, signage displays and plant trellises.  We would like to discover if we are advertising in the correct magazines and websites, and based on this, if we should increase or decrease our spending in said magazines and websites. Are there additional places we should be, should we utilize social media, should we attend more trade shows, etc. Willing to start from scratch as far as evaluating our message and materials.  As it is now, we advertise in architectural magazines and specific websites. Current budget between $100,001- and $250,000.