Hey, I tried posting in here some links for you before, but my comment didn't get accepted. damn!
You can get those timberland boots on ebay if you go to ebay. co uk - I bought some for Lara in the colour Taupe, as they look dark in photo's anyway. they do ship worldwide.
Timberland also do a really nice pair of tight fitting combat pants, which are on amazon UK.
Have you tried sculpting her pendant out of FIMO? I thought her design was a phoenix, a maori crossed my mind but never really made sense to me as to why she had it. (assuming that she didnt have the pendant at the beginning, on the endurance.)
as for drop leg holster, I made mine using craft foam and some gorgeous distressed leather effect material bought from on ebay. i spent no more than about £15 to make it, thats including the d-rings and rivets too!
Can't wait to see some more of your progress. ^^