Wednesday's clash will see Germany's top two teams meet in the final round of matches before the January winter break.
Leipzig knocked Bayern, who are at bottom side Darmstadt on Sunday, off the top of the German league on Saturday with a 2-0 win over fourth-placed Hertha Berlin.
Goals either side of half-time by striker Timo Werner and burly centre-back Orban sealed the win at Leipzig's sold-out Red Bull Arena to leave RB three points clear.
Bayern can regain top spot with three points at Darmstadt, because of their superior goal difference.
Regardless of the Darmstadt result, Wednesday's clash at Munich's Allianz Arena between Bayern and Leipzig will see Germany's top two teams meet in the final round of matches before the January winter break.
Either centre-back Orban, 24, or midfielder Dominik Kaiser, 28, will lead RB Leipzig out for the first time in the club's brief seven-year history against Bayern's star-studded squad.
"We want to give it everything we have, the anticipation is already very high, because it's an absolute highlight," said Orban, who captained Leipzig against Hertha with Kaiser on the bench.
"Bayern are, of course, a top team, and we'll need a top performance in every position if we want to take something from there. 100 percent.
"We want to show how far we have come and prove that we can put in our best performance when it matters. Then we'll see if that's enough.
"We need to recover well first, but I can hardly wait for the game."
Leipzig responded to last weekend's shock 1-0 defeat at Ingolstadt with a polished display as Orban's powerful header on 62 minutes put the game beyond Hertha.
"It was a nice moment for me, to be able to help the team, because at 2-0 it pushed us forward," he said.
"It was the sort of performance we wanted after a good week of training.
"We were very good, very focused, carried out the match plan well and deserved the win against one of the top teams in the league."
Orban admitted he was relieved to have come through the 90 minutes without a yellow card.
A fifth booking this season, against Hertha, would have seen him suspended to Wednesday's crunch clash.
"I wasn't thinking about it during the game, but I sure was before, so I'm glad I didn't get a booking, because it would have been bitter if I had missed the Bayern game," he said.
RB Leipzig were only founded in 2009 when Austrian drinks giants Red Bull took over a German Football League (DFL) licence.
Red Bull's billionaire founder Dietrich Mateschitz, 72, made a rare appearance at the Hertha game and will be in Munich.
RB Leipzig have never lost when he has attended a match.
"He's coming too, hopefully it's a good sign," said Orban with one eye already on Munich.