I have been up Mt Kinabalu 4 times, starting in 2005 to 2008.
My last trip up was in March this year. You can look at my posting in
http://mountain-n-sea.blogspot.com/2008/03/gunung-kota-kinabalu-40952-m.html
We planned one year ahead, as the accomodation up in Laban Rata is limited, and therefore you may not have proper accomodation at the mid-point.
Climbing Mt Kinabalu does not require special gears, but still you need to train to climb the thousand of steps. Unless you are regular in exercising or a Marathon runner, you will feel the ache on your thigh, and the last thing you want is to suffer from cramps in between stations. It is not going to be fun!
Still, you may try and my gears are simple for every gram counts when you climb. A walking stick that also double as monopod; my light Nikon D70S (which has been up this mountain 3 times), my versatile 18 to 200 mm VR II. But more importantly, water, energy food (banana, raisins, biscuits, Kit Kat).
I lugged 11 kg up (food, water and gears), and I can assure you feel that it get heavier and heavier. Be prepared for adverse weather, not too sure how many people know that temperature can drop below ZERO, but my first climb in 2005, we have ice near the peak.
Alternatively, suggest that you attempt to trek from Mersilau to Timpohon (should take you about 6 to 7 hours). From 2200 m to 1800 m. In between you may climb to about 2700 m.
A quick gauge of your fitness is to try out Bt Timah (162 m), and use the off trial (from the Ranger Station go to the right, then Tiup Tiup, Dairy Farm Loop, up Tua Goo, Forest Fall Walk, and down to the ranger station) and do it 3 times. If you are in bad shape the next day, don't try to climb Mt Kinabalu, you are not readied!
Enjoy and wish you all the best.