Nikon D5000 master flash?

I'm trying to figure out what external flash I need to get that will trigger my Britek PS-300 lights? Is it only a SB900 or will a 600 work? I just need something to make them flash when I shoot.

I would consider Nikon SB-900 AF Speedlight Flash for Nikon Digital SLR Cameras

High-quality flash for standalone use or as part of a comprehensive lighting system
Commander mode controls up to 3 Speedlight groups or unlimited individual Speedlights
4 wireless channel options; prominent master and remote control switch for wireless operation
Auto power zoom coverage ranges from 17 to 200mm (FX format) to 12 to 200mm (DX format)
3 light distribution patterns; measures 3 x 5.7 x 4.7 inches (W x H x D) and weighs 14.6 ounces