I've never been a fan of the Avalon 737. And I sure would not suggest a specific alternative without hearing the song and the vocalist first. The Avalon is an optical type and you don't seem to have anything in the same style to choose from. Do what real engineers do, use what you have available and see what works best. The 1176, dbx 165 and LA-4 are old time standards for vocals used by many including me. Your choice may also depend on what other tracks need compression or the need to use a specific compressor.