CFI-I
I answered BoDEAN on this query on the other forum, but wanted to reiterate my points for readers here.
You absolutely, positively want to get your CFI-I, and MEI. No disrespect intended to the folks who spray for bugs and fight fires, but instruments and multiengine are the essence of professional aviation. They are how people and freight-haulers do business. You want to learn as much as you can about instruments and get as much IFR system experience as possible. There is no better way to get it than to teach it, short of actually flying it, not to mention that you acquire a tremendous amount of book knowledge when you teach it.
I second Tooslow. You indeed want to present the best credentials possible. Fate sometimes controls the type and quality of experience we can offer, but we have absolute control over our certificates and educational quals. Leaving the college debate aside for the moment, there is no reason not to offer all pilot ratings, all instructor ratings, all ground instructor ratings, and your ATP when the time comes, even if you must earn it on your nickel. You short yourself against the competition if you do not offer all ratings. Offering seaplane, glider ratings, etc. are icing on the cake.