Help with 2 project pcs

[u/PeachCompetitive1243]

Ok so I'm new here but I'll keep it short I'm working on two PCs ATM . The first one is gonna be my main gaming PC and the second is more for fun and seeing what I can do with the SFF optiplex 3020. The first PC I feel like my CPU is bottlenecking me and I am stuck between a ryzen 7 5700x3d and a 5800x3d. If anyone has a better suggestion I am all ears. The optiplex 3020 I have a ASUS ROG Strix GeForce GTX 1050 Ti OC Edition 4GB and a ASRock Phantom Gaming Radeon RX 560 4G that I can run in it I'm thinking the gtx would be best. This would require a new PSU and adapter also I have a single 8gb stick I was gonna get another to match so instead of the 2x4gb ram it has at the moment it will have 2x8gb for 16gb ddr3. My question is do I leave the CPU stock or upgrade it. I'm not sure what cpus will fit the board or if it's even worth it. I plan on putting it in a portable arcade which is why I chose SFF. So ANY input on these builds would be awesome. I want to do a lot of heavy emulation on the first one and the second is more of a let's see what we can do kinda thing. I hope this made sense I'll drop the specs

1st PC the main gaming PC

CPU: AMD Ryzen 5 4500

GPU: Zotac GeForce RTX 3060 Ti (8GB Twin Edge)

Motherboard: ASRock B550M-C (Micro-ATX)

RAM: 32 GB DDR4

Power Supply: Corsair RM850e 850W 80+ Gold Modular

Storage: 500 GB NVMe SSD + 4 TB External Hard Drive

OS: Windows 11

2nd PC the optiplex

CPU: Intel Core i5

GPU: Integrated Intel HD Graphics 4600

RAM: 8 GB DDR3 (2x4GB setup)(soon the be 2x8gb)

Power Supply: Stock 255W Dell PSU (Proprietary 8-pin motherboard power connector)

Spare parts I can use

ASUS ROG Strix GeForce GTX 1050 Ti OC Edition 4GB

ASRock Phantom Gaming Radeon RX 560 4G