Redirect headers

When I have a product that’s discontinued I want to give the customer a link to an alternative product, but how do I give this information to search engines?

Is there some header which says ‘display this page, but in the future you want to be going to another page’? I don’t want to silently do a 301 redirect, because then the browser might feel mislead.

Or, would I just have to rely on putting a link to the new product page?

303 “See Other” ?

A 303 will silently redirect the the user, won’t it? I want the customer to see the page they requested, and will be told the product’s no longer for sale and they should look at this other page.

Why not display that page for the visitor/user, then use a 303 for search engines? Viable?

Bot detection - that’s a whole big issue, but isn’t it a bit imprecise?

I would avoid this for risk of getting blacklisted by search engines.