Go with 2x16GB.

Two sticks is almost always better for Ryzen 5000.

The memory controller on these CPUs prefers fewer ranks per channel. With 2x16GB you’re running two dual-rank sticks (assuming standard 16GB DIMMs), which gives you the same rank count per channel as 4x8GB would — but without the extra electrical load. That means higher frequency and tighter timings are easier to achieve. Most kits rated 3600MHz CL16 will actually run at those numbers with two sticks. With four, you’re rolling the dice.

Also, you keep two RAM slots open for future upgrades. Going 4x8GB locks you into 32GB forever, unless you toss a pair.

The only reason to go 4x8GB is if you already have two 8GB sticks and buying two more is cheaper than replacing them. But for a fresh build? 2x16GB every time.

Future You will appreciate the easy 64GB upgrade later.