I'd go with the marinate and grill. A nice steak
deserves no less than a searing hot grill.
This sounds like the perfect opportunity for you
to develope or fine tune your own marinade.
Whether you use a mix of spices and herbs of
your own or one of the pre-mixed off the shelf
(some of which are very good) remember this:
ALWAYS start with extra virgin olive oil.
From there, soy sauce, worcestershire sauce or
Louisiana hot sauce (or a mix of 2 or more) and
then of course fresh cracked black pepper, grd cumin,
rosemary, ginger, garlic.... you get the idea.
Marinate a couple of hours, the last of which covered
on the counter allowing the meat to come up to room
temp. (cooks better) and then put on the hot grill
diagonally for a couple of minutes, turn over for a
couple of minutes, turn over to the opposite diagonal
direction a couple of minutes, turn over again, 3 minutes
later put on a platter, cover w/ foil for 10 minutes and
you should have a wonderful medium rare steak with
nice criss-cross grill lines. Very appealing to the eye
as well as delicious.
(Note: propane and propane products are the way
to go whencooking steaks. The key is HOT GRILL)

PK