Well as a man who loves the fadangling of the rules I suggest the following...
I - Get your hands on the Revenant rules (Which I assume you have)
II - Get your hands on the Epic
40k Eldar rules
III - Find a way to reverse engineer the Epic rules with the Revenant to match up to the
FW rules
IV - If you can desern a system to it, reverse engineer the Epic rules for the Knight titan the same way...
V - I have no idea how you would go about deciding a point value? Maybe a middle ground between a Wraithlord and the Revenant
Hope it helps, Precision games has Epic rule books (I think it's Precision, Jervis Jhonson's company)
Usiel