Are you looking for just a company that can supply/install barriers & paint lines or are you wanting a review and improvements/design of your warehouse layout which includes physical pedestrian/traffic management safety solutions?
If it is the second, I used to work with a guys who now runs a small logistics consultancy that may be able to help out, even just from a point of view of clearly defining the scope and assessment/development of the initial concept design which can lead to a better end result of the procurement / RFP process.

His name is Richard Mahoney from Studio Logistic

contact Matt Strickett at Dexsafe (Dexters).
https://www.dexsafe.com/nz/
https://dexters.co.nz/

Contact Vanguard Group NZ (Brendan McLean) is the Director. They install traffic bollards, barriers, vehicle and pedestrian equipment. Their number is 0800 500 147. Brendan's email is:
brendanatvanguardgroupdotcodotnz.

Thank you, I have already contacted Vanguard but was looking for a second option.

Thanks Wayne PS nice to see you outside of the "old employer" lol

HI I would recommend Fisher Painting Services 09 390 4299. Line Marking Solutions also - Stephen O'Neill 0800 080 074 - I got some excellent quotes from these companies for pedestrian marking and and segregating forklift and truck traffic areas.