I just finished the Extra, and have now got a few flights on it.

With the 1.80 you will need a bigger fuel tank. I would recommend a 24 oz minimum. I haven't weighed mine yet, but I would bet it is at least 13 pounds. I would also swap out the wheels, they will not last.

As to the engine, my choice would be a 1.60FX 2 stroke, but I'm partial to 2 strokes. Cheaper and more powerfull.