Cache Only or Zone DNS?

Currently we use Wins for name resoluation, and have a outside DNS available for use for outside name resolution. W2k is not on the table.

My questions are these:

1. If we put a DNS inside LAN (no outside access), will the traffic on the WAN (T1) be increased or decreased, compared to the current configuration? I am concerning those traffic related recursive queries.

2. If we do put a DNS inside, better to associate some zone information or just to store cache? Since the Wins will be still used (we have 95, 98, 4.x), only a few server names will be added into the zone file.

Thanks!