Flipped the coin for mechanics or C&V looking for input

I amfixing up my mother-in-laws early 80's univega for my son (he still likes his bmx...but was intrigued by the speed of the univega)

I have two sets of wheels both 27."... the ones from the univega and a set from my '82 nishki. The wheels as similar/typical sunshine hubs araya rims. The univega are high flange and the spokes really rusty because the bike was in a garage near the ocean, so I plan on using the ones from the nishki. Te spokes are going on the Niskhi also...a couple of broken.

So what you do you think

a) just replace the broken spokes as they go
b) bite the bullet and rebuild the wheels
c) or grab a cheap pair of 27 or 700c wheels

and unrelated.....grab a new freewheell or just go with the old one

I am trying to avoid sinking a lot o money into the project....but you know how that goes

thanks