I used a couple heatsinks like
https://www.ebay.ca/itm/Heat-sink-10...4n8z:rk:1:pf:0
Also use some thermal paste between the heat sinks and the resistors.
Resistors like
https://www.ebay.ca/itm/25-50-100W-0...ODhA:rk:6:pf:0
You can use some scrap solid bare wire from a new house being built. Personally I just used some 12 gauge stranded wire I had lying around. It was a little trickier to solder but not to difficult. I would aim for a minimum of 14 gauge.
For fans you can use PC fans I'm trying to find some of those nice fans that are built around heatsinks.