Sadly an i5 NUC is doing it for me.
I fondly recall forcing a dual loop water system into the smallest case I could but OMG the time and money.
I had a photograph somewhere of a £2k bootfull when I went to OCUK many moons ago.. (2x 7800gtx sli when sli was shiny new and an AMD X2 lol) despite having a significantly higher income now my priorities have realigned somewhat.
To be fair all this hard tubing and tons of device specific and AIO coolers has taken the challenge out of it IMO.
Back in the noughties we were often using PTFE tape and aquarium pumps..
Kids these days