There is a lot of useful information and discussion on Lupron vs. surgery
in the archives, so I will direct you there.  However, your post contains
two sentences which concern me.
 
1) Pre-op bloodwork was normal, but he bled from both legs after they took
blood.  While this might be something as simple as not keeping pressure on
the venipuncture site for long enough, I would also enquire if a platelet
test was run.  I recently lost on of my own following surgery when the
platelets were markedly decreased (even in spite of a pre-op transfusion.)
I am always concerned when excessive bleeding occurs.
 
2) Your vet plans to close up the ferret if a right adrenal lesion is seen.
This is not really an appropriate way to do surgery - if your vet is not
comfortable in working around the right adrenal, perhaps another vet may
be consulted.
 
Lupron is not a good option in so young a ferret - as far as we know it
only blocks estrogen's effects, but does not treat adrenal lesions
directly.  It may be used in older ferrets who are not surgical candidates,
but in a young ferret it poses unnecessary risk and over time, will be more
expensive than surgery.
 
With kindest regards,
Bruce Williams, DVM
http://groups.yahoo.com/group/Ferret-Health-list
[Posted in FML issue 3512]