HORSEINAROUND

I JUST PURCHASED A SINGER 29K60. I HAVE RESEARCHED (THAT WAS INTERESTING) FOR INFORMATION ON THE CORRECT NEEDLE FOR THIS MACHINE AND WHAT THE PROPER THREAD WOULD BE FOR 8/9 OZ. LEATHER. I COME UP WITH AT 92 OR 138 BONDED NYLON FOR THE THREAD AND 123 HEAVY DUTY NEEDLE. IF SOMEONE WOULD CLARIFY THIS OR POINT ME IN THE RIGHT DIRECTION I WOULD TRUELY APPRECIATE IT. THANK YOU