I'm in a similar position. As far as I know, the bottleneck on the Pi is the USB connection to the SSD. I bought a second hand thinkpad i5, 8 Gb RAM for 130$. It has dual storage capability for RAID, new battery as backup, it will only be used as node. But for now I'm learning like a maniac, just installed CLN and learning to use terminal, linux and the barebones of it all. I recomend for learning https://www.youtube.com/c/402PaymentRequired/videos and https://darthcoin.substack.com/p/lightning-node-maintenance?s=r