I also love imitators as stated above, those would been my first choice if they weren't more then double the price of the vents. I didn't want to try my hand at 175$ frogs first shot. Later one when confidence and ability has built up then the more expensive frogs will come.
Not to say losing a vent wouldn't be just as important as losing an imitator, it's just the monetary aspect of it.
Any of the choices above I think the OP will be very happy with
