If you want to build and the money is not too tight, I would get an RTF/ARF and a kit of a like style trainer. One gets you in the air fast; the other is going to do a couple of things. One it can be a back up; as with training, the planes get beat up a bit. Second, trainers are the easiest to build and getting your feet wet with them can show you a lot of things before you build your dream plane instead of panics over details with that one. Your skills are also equal being a beginner. Once you can fly well you wont want to build a trainer. To make it different from the primary plane you could build the wing flat making it a bit more aerobatic, make it a tail dragger makes you know how to handle one, add working flaps something to play around with; things that will add to your abilitys but not too far of a stretch if the plane had to be pressed into service after the demise of the other.