Still not clear exactly what you're trying to do, and exactly what the problem is. What is being used for the system clock, and what is the 32kHz crystal connected to? If you're clocking timer 2 from the 32kHz crystal, then that is not the system clock, so it can can't be output to the CLKO pin. One second in 5 min is 3333ppm, so something is terribly wrong. What is the load capacitance spec for the crystal? I've got a lot of DS1307s with 32kHz crystals around, most run within 20ppm, although I do have one or two flyers. I'd go for a Chronodot (±2ppm) or something similar before I'd go for that $12 TXCO (±7.5ppm).
A lot of the 32.768kHz crystals that get used with DS1307s have a load capacitance spec of 12.5pF. These will also work to clock timer2 asynchronously; I've done this once or twice just playing around, but haven't measured the frequency.