You need access to the windows sdk for the constants, the files winuser.h and commctrl.h in particular.
Longs and ints are both 32 bit values in win32 so you should be fine.
From reading the notes in MSDN you might not see a style changes take effect until you resize the gadget.
/*
* Window Styles
*/
#define WS_OVERLAPPED 0x00000000L
#define WS_POPUP 0x80000000L
#define WS_CHILD 0x40000000L
#define WS_MINIMIZE 0x20000000L
#define WS_VISIBLE 0x10000000L
#define WS_DISABLED 0x08000000L
#define WS_CLIPSIBLINGS 0x04000000L
#define WS_CLIPCHILDREN 0x02000000L
#define WS_MAXIMIZE 0x01000000L
#define WS_CAPTION 0x00C00000L /* WS_BORDER | WS_DLGFRAME */
#define WS_BORDER 0x00800000L
#define WS_DLGFRAME 0x00400000L
#define WS_VSCROLL 0x00200000L
#define WS_HSCROLL 0x00100000L
#define WS_SYSMENU 0x00080000L
#define WS_THICKFRAME 0x00040000L
#define WS_GROUP 0x00020000L
#define WS_TABSTOP 0x00010000L
#define WS_MINIMIZEBOX 0x00020000L
#define WS_MAXIMIZEBOX 0x00010000L
#define WS_TILED WS_OVERLAPPED
#define WS_ICONIC WS_MINIMIZE
#define WS_SIZEBOX WS_THICKFRAME
#define WS_TILEDWINDOW WS_OVERLAPPEDWINDOW
#if (_WIN32_IE >= 0x0300)
#define TCS_SCROLLOPPOSITE 0x0001 // assumes multiline tab
#define TCS_BOTTOM 0x0002
#define TCS_RIGHT 0x0002
#define TCS_MULTISELECT 0x0004 // allow multi-select in button mode
#endif
#if (_WIN32_IE >= 0x0400)
#define TCS_FLATBUTTONS 0x0008
#endif
#define TCS_FORCEICONLEFT 0x0010
#define TCS_FORCELABELLEFT 0x0020
#if (_WIN32_IE >= 0x0300)
#define TCS_HOTTRACK 0x0040
#define TCS_VERTICAL 0x0080
#endif
#define TCS_TABS 0x0000
#define TCS_BUTTONS 0x0100
#define TCS_SINGLELINE 0x0000
#define TCS_MULTILINE 0x0200
#define TCS_RIGHTJUSTIFY 0x0000
#define TCS_FIXEDWIDTH 0x0400
#define TCS_RAGGEDRIGHT 0x0800
#define TCS_FOCUSONBUTTONDOWN 0x1000
#define TCS_OWNERDRAWFIXED 0x2000
#define TCS_TOOLTIPS 0x4000
#define TCS_FOCUSNEVER 0x8000
Longs and ints are both 32 bit values in win32 so you should be fine.
From reading the notes in MSDN you might not see a style changes take effect until you resize the gadget.
/*
* Window Styles
*/
#define WS_OVERLAPPED 0x00000000L
#define WS_POPUP 0x80000000L
#define WS_CHILD 0x40000000L
#define WS_MINIMIZE 0x20000000L
#define WS_VISIBLE 0x10000000L
#define WS_DISABLED 0x08000000L
#define WS_CLIPSIBLINGS 0x04000000L
#define WS_CLIPCHILDREN 0x02000000L
#define WS_MAXIMIZE 0x01000000L
#define WS_CAPTION 0x00C00000L /* WS_BORDER | WS_DLGFRAME */
#define WS_BORDER 0x00800000L
#define WS_DLGFRAME 0x00400000L
#define WS_VSCROLL 0x00200000L
#define WS_HSCROLL 0x00100000L
#define WS_SYSMENU 0x00080000L
#define WS_THICKFRAME 0x00040000L
#define WS_GROUP 0x00020000L
#define WS_TABSTOP 0x00010000L
#define WS_MINIMIZEBOX 0x00020000L
#define WS_MAXIMIZEBOX 0x00010000L
#define WS_TILED WS_OVERLAPPED
#define WS_ICONIC WS_MINIMIZE
#define WS_SIZEBOX WS_THICKFRAME
#define WS_TILEDWINDOW WS_OVERLAPPEDWINDOW
#if (_WIN32_IE >= 0x0300)
#define TCS_SCROLLOPPOSITE 0x0001 // assumes multiline tab
#define TCS_BOTTOM 0x0002
#define TCS_RIGHT 0x0002
#define TCS_MULTISELECT 0x0004 // allow multi-select in button mode
#endif
#if (_WIN32_IE >= 0x0400)
#define TCS_FLATBUTTONS 0x0008
#endif
#define TCS_FORCEICONLEFT 0x0010
#define TCS_FORCELABELLEFT 0x0020
#if (_WIN32_IE >= 0x0300)
#define TCS_HOTTRACK 0x0040
#define TCS_VERTICAL 0x0080
#endif
#define TCS_TABS 0x0000
#define TCS_BUTTONS 0x0100
#define TCS_SINGLELINE 0x0000
#define TCS_MULTILINE 0x0200
#define TCS_RIGHTJUSTIFY 0x0000
#define TCS_FIXEDWIDTH 0x0400
#define TCS_RAGGEDRIGHT 0x0800
#define TCS_FOCUSONBUTTONDOWN 0x1000
#define TCS_OWNERDRAWFIXED 0x2000
#define TCS_TOOLTIPS 0x4000
#define TCS_FOCUSNEVER 0x8000