I thought I should create this to share my experience so far and ask for help.
the specifications are as follows.

Mobile 915GM/GMS/910GML Express Graphics Controller
AR5212 802.11abg NIC.
SATA 40 G Hard drive.
NetXtreme BCM5751M Gigabit Ethernet PCI Express
82801FBM (ICH6M) SATA Controller
AC'97 Audio AD1981
According to my research above component have been made to work with osx86 in one laptop or the other.

OSX86 distros.

IPC 10.5.6 PPF final osx86 dvd. as well as

Idenib ver 1.5.1 osx86.

Here is the summary of my ordeal.

Idenib installs perfectly even with no options selected. However, at the reboot it go to apple logo and then suddenly a box displayed asking me to reboot the machine. Machine does exactly the same on reboot. so it is kinda endless reboot loop.

I inserted the install DVD and push f8 during boot. at the prompt I entered rd=disk0s1 and it started booting from the hard drive. Osx86 boots. However, it seems that no kext are loaded at this stage. I abandoned this as I dont want to use install DVD every time I boot osx86. I tried the Idenib dvd with my work Lenovo T61 and it had the same issue. endless reboot loop.

Then I started experimenting with iPC 10.5.6 Final PPF. First I gave it a go on Lenovo T61 and it smoothly installed with no options selected. It booted OK as well. However there was no display or WIFI existed. This encouraged me a bit.

I then tried it on Lenovo/IBM X41 Tablet. It installs smoothly. However I have tried mulitple combinations of kexts/kernel and bootloaders but system stucks on "waiting for the root device" on first reboot. Again it is possible to boot the system using install DVD method ( above ).

I guess it is a good news in a way that I can boot the system and modify the status and all is not lost but I dont know what I should do to make it boot from the hard drive.

the Bios doesn't have the option of changing SATA or ACHI as described in various guides on X41. May be some one can use this information to provide some guidance.

For Atheros AR5212 card, I have used IO80211Family.kext from IPC DVD with no other mods and it doesn't work for my card.

I am trying to take one problem at a time so priority is to install it and boot from the hard drive without "still waiting for the root device".

any help will be appreciated.