I recall AshesZ did a write-up on how to convert your stock into a "real" BOV. However, if you *MUST* have a BOV, go with Tial or HKS.
'03 Nissan 350Z Touring 6 Aero Super Black Stage Stock '97 Nissan 240SX S14 SR-Turbo Obsidian Black Stage X '90 Nissan 300ZX Twin Turbo Aztec Red Stage XIII