After experimenting with a long running average at maxed out FPS and a variety of map sizes, 128 seems to actually be a good size to use if only drawing bits of world with stuff in it. 64 actually did even better in some situations, but significantly worse in others (lots of land, zoomed out).
/*
** $Id: lstring.h,v 1.43.1.1 2007/12/27 13:02:25 roberto Exp $
** String table (keep all strings handled by Lua)
** See Copyright Notice in lua.h
*/
#ifndef lstring_h
#define lstring_h
#include "lgc.h"
#include "lobject.h"
#include "lstate.h"
#define sizestring(s) (sizeof(union TString)+((s)->len+1)*sizeof(char))
#define sizeudata(u) (sizeof(union Udata)+(u)->len)
#define luaS_new(L, s) (luaS_newlstr(L, s, strlen(s)))
#define luaS_newliteral(L, s) (luaS_newlstr(L, "" s, \
(sizeof(s)/sizeof(char))-1))
#define luaS_fix(s) l_setbit((s)->tsv.marked, FIXEDBIT)
LUAI_FUNC void luaS_resize (lua_State *L, int newsize);
LUAI_FUNC Udata *luaS_newudata (lua_State *L, size_t s, Table *e);
LUAI_FUNC TString *luaS_newlstr (lua_State *L, const char *str, size_t l);
#endif