2x3090 setup, need some recommendations

So i finally decided to get myself a dedicated inference machine, a big upgrade from my 4080 laptop. here is the parts list: PC Build Cost Breakdown ASUS TUF RTX 3090 — $927 64GB DDR4 4000MHz RAM — $371 Case — $72 Ryzen 7 5700X — $181 CPU Cooler — $27 PSU — $268 Thermal Paste — $12 1TB NVMe SSD — Already owned X570 Unify Motherboard — $185 RTX 3090 Suprim X — $1,010 Ethernet Cable — $11 PCIe Riser — $82 Custom PSU Cable — $13 Total: ~$3,157 im probably gonna upgrade to 128gb ram and get a better pcie riser cable. the problems i faced initially were finding a proper way to add the 2. gpu. there