May I know where can I find taylor who specialise in sewing custom made cheongsam? Shops or home based are fine as long as located in KL or PJ.

If you ever go to Thailand, like Bangkok, there's a lot there. Much cheaper as well.

does anybody know where can custom made cheongsam/qipao? roughly how much does it cost to make a knee length lace cheongsam?

You can easily get one in The Curve at a reasonable price, quite decent design as well