I was wondering if someone could help me how to manage temporarily inactive website in regards of SEO and search engine.

the case is i managed a big ecommerce site, and sometime i need to put down page(s). could be days, could be weeks, could be months, and it depends on our vendor.

if my visitors land on the page that been temporarily inactive then i can give them a message that the vendor they looking for is not available at this time and he can check back later OR check another vendor with similar products, but how do i send my message to search engine robots?

if i use 301 status and forward URL page to another similar products, then the chance that the current URL being deindex is huge while i still want to use that URL for the future if my vendor want to re-join.

any advise will highly appriciated