ussuly a 3 day turn over on orders. depending where you live, here is a link,
http://www.grainger.com/product/TENNSCO-Bulk-Storage-Rack-Add-On-Unit-WP110472/_/N-/Ntt-open+frame+shelf+rack+5+shelf?sst=subset&suggestConfigId=6&s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/7B334_AS01?$smthumb$
Check out www.uline.com. I wonder if they would carry. It's a industrial storage and package handling company
They have cross bars for those racking styles as well as a steel grating. I work for a beverage manufacturer. We use these with a 10 ft span and two cross bars to hold 2 pallets of BIB. That's around 3200 ibs. also some of our lift operators are not the best and put frequent abuse of these stands. I do not see an issue with them supporting a tank or two.