Crossword Compiler for Windows (CCWin) has a feature that might help. (Might be in the CCWin Pro version, not the basic version.) It consists of an expandable library of empty grids. When you start a new puzzle the program shows a panel asking what type of puzzle ... cryptic, "American," Sudoku, shape, etc. If you select "American" and then "15x15" you will see a list of grid parameters on the left with the highlighted one shown in a preview pane. The "Grid Library" pull-down offers sorting-display options, including "number of words and blocks" and "sorted by word lengths." Additionally, you can supply a list of theme entries and CCWin will show you the library grids that can accommodate those entries. Hope this helps.
-Mel
