Don't get lead free solder, stick with the Leaded solder, its better. Lead free solder joints will eventually crystalize after a few years, since there is no lead to prevent that from happening, and I dont believe that would be good for your repairs.

I have a 60W from Plusivo I got for $20 on sale, and its held up for 2 years already.

How much did you pay for your 40W and 48W?

Also I see you picked out the Esmetium stuff, but here is another low cost high quality solder if you are interested: https://www.amazon.com/wyunway-Solder-Electrical-Soldering-weight/dp/B0BX9M7QV8/ref=sr_1_10?crid=Z7LKMLNVGYQF&keywords=63%2B37%2Bsolder%2B1lb&qid=1683001604&sprefix=63%2B37%2Bsolder1lb%2Caps%2C176&sr=8-10&th=1