At the moment I'm writing on a program to fill a database with product information. I've got a list of categories, from which i need the 20 best products from Amazon. Since i only got a keyword list of them and no BrowseNodes, I can't search in other SearchIndexes  then "All" with the Amazon API. This leads to alot of false Products. 
For example the categorie "tennis bat" gives me about 12 real tennis bat's and 8 other things for tennis, for example a damper, tennis bags or sometimes things completly unrelated.
I've also found no reliable way of getting the BrowseNode of a categorie. 
I've tried to search for Items with the Keyword and getting the BrowseNode of the first Item, but not only does those products have many different BrowseNodes, but sometimes they dont relate to the keyword at all.
I also can't search for them manually, because the list of categories is over 700 by now.
Would love any input on my problem.
The only answer I've found so far, is manually choosing BrowseNode and SearchIndex
Get best products of an Amazon categorie