question about thermal cooling metals, part 2

I saw a thread about this, and it seemed like everybody said that copper would keep coldest the longest. this is my problem that i need help with, I'm working
a sushi catering company. I need to keep the sushi, cold, and presentable. if you google cooling trays there is a block of stainless steel for $89 with little feet pads for sale, that you stick in the freezer than take out. I feel like there is a better option, like i could go get a chunk of metal from somewhere right? and if I can, what is the best metal + volume i should get for this application. i want to be able to put at least 120 pieces of sushi on one.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dear aesosa:
On Saturday, November 25, 2017 at 11:18:10 PM UTC-7, aesosa wrote:

Why not ice blocks, which provide a phase change.
David A. Smith
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.