Building a RIMS system help

Hey guys currently I'm working on upgrading to a RIMS system. The design I found calls for 2" Stainless steel fittings. All said and done the fittings for the element chamber in SS come to over 200$. Much more then is in the budget. Can you use copper, or brass? Does the chamber need to be 2" diameter seeing as the element is threaded for a 1" hole. I appreciate your help, pictures of your non SS RIMS heating element chamber welcome. Thanks.

We used copper on one and it worked fine. Currently for sale as well if you're interested.

https://www.homebrewtalk.com/f16/copper-rims-tube-fs-379690/

I have a 1.5" kit available for $72

Bobby_M said:

I have a 1.5" kit available for $72

Click to expand...

Thanks for the tip, you have a great site too. I will keep you in mind.