Depends how big your .10/.20 game plays, but if it's a bit splashy I would do .10/$1/$5(/$20) . Over here in Norway the standard poker club games are played 10/20 (NOK), with 10/100/500 denominations and that works well for NLHE/PLO.
It works well enough with 1 rack of 10s with a dedicated dealer that can make change, but I would prefer 2 racks of 10s pr table with no dedicated dealer. Keep in mind that the American culture of having racks and racks of chips in front of every player is not really a thing here. As a chipper I'm sometimes annoyed with having only one rack of 10s on the table, and would prefer the following start stack for a 2000 buyin:
20x 10 chip
18x 100 chip
This would be 20x 10c and 18x $1 chips for your set. You can probably do rebuys in mainly $5s, but just add however many racks of $1s you would want on the table.
It does depend on how big the game plays though. Honestly more often than not the 10/20 games here have standard opening raises of 100 or 120. I think that is because it's small money to some of the splashier players, but the lack of 10s on the table could also have an impact here. The games play pretty big though, and very often straddled to at least 40. If your game plays smaller it might be different.
For what it is worth I have just ordered a set with this breakdown for playing NL10/20 and FL20/40:
800x $10
300x $100
100x $500
Some stack pictures from some of the clubs I've played in over here:
In the last picture you can see it's sometimes a bit ridiculous if there's small amounts of lower denoms on the table, but I think with a couple of racks of 10c and $1s on the table, and some $5s as value storage you should be pretty good!