I recommend Canon over any other brand. They have the most intuitively designed functions allowing more ease of use in the field.
Canon Digital Camera Bodies
Canon Rebel Series: Five EOS Rebels currently available. All good entry SLRs to fit any budget and file size needs.
Canon more advanced: 50D, 60D, 7D, 5D Mark II. For the more dedicated photographer.
Moderate Price EF & EF-S
Wide angle focal length for extreme depth of field images: Canon 10-22mm f/3.5-4.5
Medium focal length:
18-55mm f/3.5-5.6 IS (image stablization adds up to 3 stops hand-holdability)
Telephoto focal length: 70-300mm f/4-5.6 IS
Best Quality L Series Pro Lenses
16-35mm f/2.8 L (best with full size sensor camera 5D Mark II)
24-105 f/4 L IS
70-200 f/4 L IS
100-400 f/4.5-5.6 L IS
Bogen/Manfrotto 190XB with ball head or pistol grip head. The 190 series is a good size for 35mm cameras, but if you want more support and height check out the 055 series.
Lowe Pro Rover AW II is a good backpack for a camera body and several lenses, plus room for raingear and lunch. The Tamrac Adventure 10 is a bit larger and works the same way. B & H Photo is a good, reliable resource from which to get gear online. But locally, Mike’s Camera carries all of this gear, too, has great service with very reasonable prices. In addition, you’ll need a cord or cordless remote shutter release. Otherwise, you’re stuck using the 2/10-second timer release, which is okay at 2-seconds, but not at 10-seconds when flowers are moving.