Best bet would be to start with a second hand set with some lenses, you can find those for even under $350. Use the rest to get a good tripod, flashgun and a bag for all stuff. Extra batteries come in handy too.

My set consists of a Canon EOS 550D (Rebel T2i), Sigma ART 50 mm 1.4, two kit lenses, an ultra wide angle zoom, and three vintage primes.

If you need weather proofing, consider Pentax, they have good, affordable weather proofed cameras with a wide range of lenses.