RE: Which Sig?
After my high wing trainer I got a 4*40. 6 month later I got the SSE. I still do not think the SSE is docile enough for first low wing plane - at least it is not as forgiving as the 4*. For me this was an excellent transition. BTW I flew the high wing trainer for 3 months. I had it overpowered (a lot) and tore the wing at full throttle (forgot the overpowered thingie - had too much fun with it). I missed having a trainer in my collection so I scratchbuilt one from coro and gutter pipe and I'd fly it occasionally for fun.
I might be too slow in learning to fly - seems for others to be OK to step up to the SSE straight from the high wing trainer. For me the 4* was an excellent transition and I still love to fly it.