Low Power Hardware/Software Recommendations for Archive Node

Our startup is looking to move some of our cloud services to on-prem. First up is our mainnet RPC provider. We're looking for recommendations for low-power archive node setups (power costs are ~$0.50/kwh where we are, although we recently installed a 6000 kwh/yr solar array). We're mostly interested in hardware recs but if anyone has noticed significant power consumption discrepancies between clients, that would be cool to know as well. We're not interested in staking atm but may be in the future. Any help is great appreciated!

Further context: We make ~500k-1M RPC calls/day