Easiest route would be Kyrgyzstan through to China then Laos. From there Thailand and down the Malay Peninsula.
China will require a guide and fixed itinery usually in a group and you I think, need a Carnet for Loas and other countries in SE Asia. Shipping out of KL or Singapore shouldn't be a problem. Expensive trip though.
G
This year I went to Mongolia for the second time.
Last year I went to Mongolia not by choice as we were going through the route That Griff suggested above but the Chinese would not allow transit from Kashkar province into any other part of China so we had to exit into Mongolia and reenter into China via another route .
3 days before we were meant to reenter the Chinese stopped our vehicle permits so we were stuck in Mongolia without Russian visas.
The Motor Bikes that I was travelling with flew them to Bankok but I had to arrange a transit visa though Russia and it was only 10 days so had to cover 6000 miles in 10 days.
When I was in Mongolia this year the Tourget pass was closed to tourists as there were Riots in Turpan.
So the moral of this story is no matter how well your trip is planned the Chinese can stuff you about.
You do not need a Carnet for Laos but you do need one for Iran and Pakistan
when driving though China you have to carry a guide with you and has to be arranged though a Chinese tour company If you dont have room for a giude in your car then you have to hire a 4wheel drive and driver to carry the guide.
on the whole its expensive and although you can camp most times the guide will direct you to selected hotels that are allowed to cater for tourists.
As for Singapore for shipping out your vehicle it would be better to ship out from Kula Lumpor as getting your car into Singapore is expensive.