Is this for another bike? I thought your BIL’s Excalibur was your new ride.
I wouldn’t waste time or money on the best V-brakes. Anything that still uses them probably isn’t still living the life of a high performance race rig.
Any modestly priced Tektro will be a perfectly fine replacement.
Your brakes probably aren’t beyond repair. Lube in the pivots, new brake pads, and new cables and housing is probably all you need.
Buy new if you want, they aren’t expensive. Make sure to put new cables and housing on the new ones too.