Hi Manolo , as you are new at this I would strongly suggest you spend your next few hundred dollars on books . These are really the key to becoming an astute collector and being able to assemble a worthwhile collection .
As for keris I would suggest you read these two rather long but very informative threads from our old UBB format forum .
http://www.vikingsword.com/ubb/Forum1/HTML/000307.html
http://www.vikingsword.com/ubb/Forum1/HTML/000402.html
A copy of Stone's is a good first building block ; this book has been recently republished by Dover Press and you may be able to find a copy at either Amazon or Abebooks.com .
There is also a wealth of information to be found using the search function on both this and the old forum .