Jerry, no, you shouldn't back off on the HT idea, but simply adding a separate center speaker doesn't go very far in getting you there. A separate center speaker does have some advantages over just using the mains to form a "phantom" center; the dialog is anchored to the center for off-center listeners and the volume for the center channel can be raised independently to make low-level dialog easier to hear. However, in my view the order of priorities for an HT setup is mains, surrounds, sub and then a separate center.
If wall mounting is completely out for the surrounds, the speakers, preferably QSs, can be placed on stands in the back corners. There are even techniques such as putting the speakers on the floor in the back corners, and firing up toward the ceiling, which provide a reasonable if not ideal surround effect.
