RE: 1st low wing plane
Let's assume that you can fly the trainer properly, meaning you tell the plane where to go and it will ... the following planes are great low wing planes:
Phoenix Scanner - easy to built and will fly nice. Its cheap and will not stall easily
WM T34 Mentor - relatively cheap and it super nice to fly ... smooth as silk ... easy to fly and landings are a breeze
WM Super Sport - very agile for a low wing sport plane (mine will KE across the field without mixing), will come in for landing slightly hot unless you flare her, hence if you are really good on your trainer you can handle this one
Seagull Tucano - its nice and the new batch are very well made for its price, handles easy but not as easy as the T34 Mentor
Everyone else will recomment the 4* and Tiger II, I never had them but I guess they must be good stuff.