Firstly, a tileset:
http://alisachristopher.deviantart.com/ ... -103865969
should be useful for Stratagus based games.
The Alisa also has released huge archive of RMXP-compatible sprites. But i guess some of them could be edits, so a person with RMXP expertise is welcome to clean up this package.
http://alisachristopher.deviantart.com/ ... -483796759