On Discord groups like StockRadar you'll be able to swap info with other GPU hunters and make use of Discord bots, which are way more advanced than Twitter bots. Make sure to read the rules and customize your notifications.
If you're not the type that can code your own GPU-hoovering shop bot, you can go one of two routes. You can purchase a bot from creators like Bounce Alerts which is designed to rove online retailers in search of plunder to get the job done (these bots have already proven highly successful in doing so). Or you can turn to the crowd.
In response to a robust scalping movement, some generous souls have also decided to make, and sometimes release, their own bots for free on GitHub, though, you'll have to do some digging to find one that works for you. Reddit and Discord are probably good places to start asking around for bots to do your GPU bidding.