Early de Fiennes

Having discovered only two weeks ago that my Fines family linked back
to the de Fiennes I have been trying to make sense of the earliest
members I can find of this interesting family.
So far I seem to have found two different lineages and I am not sure
which is more accurate or if they are alternative names.
I have seen a number of websites (including Dover Castle's own) which
say that John de Fiennes was a constable of Dover Castle following the
Conquest. Several online trees show the generations following him as
James, John, Alan and then Ingelram who married Sibyl de Tingrie.
Other websites talk of Eustache I followed by Conan then Eustache II
then Ingelram and Sibyl.
I have been hunting through online discussions but I'm still not sure
whether these are different names for the same people (though the
Eustache line is one generation shorter and the dates don't seem to
match).
Please can anyone help me sort out what is well documented and what is
simply legend here? I'm a beginner at medieval genealogy and I am
feeling rather confused.

Tim Powys-Lybbe...

Have a look at Leo van der Pas' very useful list of books and their
evaluation at:

If the sites don't give a C reference, you would be better off
ignoring them.

And have you discovered Leo's massive genealogy site: