I think you are taking on a huge task and the more you ask the more I think you should sell the car and buy the right spec one in the first place.
So far you have asked about installing electric seats, heated seat, air scarf and parktronic.
None of these is even close to easy and all of these is going to be VERY expensive. I know you've bought some bits already but even if you throw these away, you'll find it much cheaper to buy the car with the right options than try to retrofit ALL of the above.
and by the way, I have not been able to answer your pm because I know nothing about combining the wiring looms for parktronic and airscarf.
I wouldn't attempt to retrofit parktronic personally, and I am more willing than most to attempt all manner of modifications.