Just wanted to let everyone know that I upgrade from Sierra to High Sierra on my laptop without any problems.
Here's what I did prior to the update:
1. Updated to latest version of Clover.
2. Placed High Sierra compatible version of apfs.efi in to /EFI/CLOVER/drivers64UEFI/.
3. Updated to latest versions of FakeSMC, FakePCIID, Lilu.
Then, I just updated to High Sierra from App Store.
Thanks once again to everyone here!!