[V8] Sodium-filled Exhaust Valves

[Stafford, Kenneth A.]

Slightly off-topic...I believe the V8's have sodium-filled exhaust valves--do any of you know where I can get some (actually for my wife's TT) other than from the stealership?  Online, I see TT valves from Osvat, TRW, and Intervalve.  I've confirmed that Osvat doesn't make any sodium-filled valves.  Where do I go?  (Btw, rather than the $6600 repair estimate for the TB failure on my wife's 1.8 225Hp TT, I opted to repair it myself.  It seems as though we encountered no damage other than 2 bent exhaust valves and 1 bent intake valve--should cost me less than $500 total.)

TIA,

Ken
91 V8Q (x2)
01 TT225