There is no need to retro a WSMs legs to get the heat shield. I have cooked hundreds of times on a wood surface. The heat from the WSM does nothing to the wood it sits on.
And I just can't see spending $$ on a leg upgrade just because it looks good. Spend that coin on meat and fuel, maybe some other mods like a second charcoal grate, handles on the center section. You know.
BTW, $80 is a good deal on a WSM. Nice score.