Hey -
Feel free to PM me about this as well, but if you're buying new, then the two best resources out there are Hugh Cameron and Mulligan and MacHenry.
Pipe snares are different in that they have a dual snare mechanism - one under the top head and one under the bottom head. Both use wire snares.
The three main pipe band drum makers are Andante (Ireland),
Premier (UK) and
Pearl (US/Japan). If you're used to
Pearl, then there's no harm in going that way, especially if you're not going overseas to compete.

Hope that helps!
Mike New
Webmaster - Silver Thistle Pipes and Drums
Austin, TX