Silos, but not as you're thinking.
The regular election will be David Perdue (R) vs. Jon Ossoff (D).
The other special election follows entirely different rules with no primary elections and 20 candidates (8D, 6R (including Loeffler, the incumbent appointee), 1 Green, 1 Libertarian, and 4 Independents) on the ballot. If no one gets a majority on election day (which looks pretty likely), then the best 2 (regardless of party, so R vs. R or D vs. D is possible) go to a runoff election in January.
https://ballotpedia.org/United_State..._Georgia,_2020
https://ballotpedia.org/United_State..._Georgia,_2020