I'm designing a new aircraft again. Started no new ones in 2010, so it's about time. It's for this competition.
There is a bit of reuse, so far the fuselage is unchanged DH 84 Dragon, which is about the right size. But it has a bit of a margin, so optimising it may bring the weight down which always is good. Getting lots of lift is easy, but as you see from the first screenshot, it's not good if the aircraft can fly before it's controllable...
I've been inspired by two aircraft. The first is the SAI KZ IV which I've seen flying and it's got really, really good STOL performance: Take off 140 m, landing 70 m! But a bit too small payload for this. Some period photographs. The other is Dornier Do 28. I haven't tried to copy them, but everything comes out looking like a bit of one or both of them.
Apart from me deciding a nose gear is better. I didn't start out like that, though.
To begin with I wanted to use Pobjoy Niagara engines. The gearbox makes the propeller sit over the engine centreline and that results in shorter landing gear. If it's on the same pod/fuselage, that is. With separate engine pods, like currently, it doesn't matter, so I'm planning on using something a bit more powerful as according to the rules a KZ IV copy will be heavier than the real one.
Regarding engine placement, I've spent a lot of time deciphering images like this (engines aren't placed symmetrically) to see which gives the most lift from the lower "blown" flaps. Seems like the forward placement is better. It's also beneficient in engine out conditions.