It depends how quickly you want to scrape your results. If you want to be aggressive and scrape with 100+ threads constantly, you'll need either a fresh bulk scraped proxy service (these are few and far between nowadays, though
@satyr85 may have one up his sleeve), or a rotating residential proxy service (which can be costly when paying by the GB).
If you're happy with waiting a while for your scrapes, a small pack of datacenter proxies will do, providing they're Google-passed. Then just use SB's detailed harvester at 1 thread, with a 30-60 second delay between searches.