If your friend has Trubine experience then the only way to go is with the F-14 even though it uses small motors (55mm). The swing wings will give more of a challenge than the F-18 even though it uses a larger motor (70mm). Too, the F-18 is listed as "super size", not much diff. when you compare them side by side. So, for the money and for someone skilled at flying the F14 would be the better choice.

F-14 F-18
★ Wingspan：1000mm/39.4in • Wing Span : 840mm(33.1 inches)
★ Length：980mm/38.6in • Length: 1200mm(47.2 inches)
★ Weight：1100g/38.8 oz • Flying Weight: 1130g(39.9 oz)