Names:
Now we have
StrToInt
StrToInt64
StrToInt64Def
StrToIntDef
TryStrToInt
TryStrToInt64
I suggest the word "Buffer" for 1-byte strings, and BufferW for widechar strings.
BufferToInt
BufferToInt64
BufferToInt64Def
BufferToIntDef
TryBufferToInt
TryBufferToInt64