Well i know nuts on this area that's why i don't mind paying a small fee for someone to do it

yes, it will solidify quickly, and they will form shiny and smooth solder joints.

it's relatively easier to melt and desolder 63/37 solder joints imo. just touch the joint for 1 to 2 seconds with hot iron (like 320c), then press the button of the desoldering pump. i use hakko sppon 20g.

if you're comfortable with 60/40, it's ok to use it also. i suggest 63/37 because it's beginner-friendly, e.g., it melts and flows nicely, so that soldering and desoldering can be done within 3 seconds per joint, even for a beginner.

edit:

this is my recent build with kester 63/37 solder wires, after IPA cleanup.