Hello, I might not be the right guy to reply, but I just recently lowered my Freetrack (on 225/45 R17), which is indeed higher as stock, but the lowering effect was stunning, and I am not a guy seeking good looks, merely improved performance, and still I like it. I used Eibach Pro-Kit springs, and if they say they will lower 25mm or 30mm, then they will lower 25mm or 30mm, this is the easiest way you can imagine the result. Possibly, depending on the state of your stock springs (what is your mileage?), if they are "tired" a bit, the lowering might be slightly smaller. This is how I changed the springs, I did not take photos, I documented the process on video, you might see how the car looked on stock springs and on lowered Eibachs.
Altea Freetrack Eibach
But still, the lowered Freetrack is about as high as yours stock, so I just to give you an idea.. As for the driving quality, I very much like less body roll and stiffer reactions (not necessarily less comfortable!) I gained with this exchange.. When you finish these tyres, I would recommend fitting 225/45/17 tyre size (which should be your native tyre size on 17"), you gain a bit on the wheel size (bigger wheel = better looks?) and a more stable ride, and they will fit your rims very well, since you have 7,5" rims.
May I ask where you got that sweet front spoiler? Is it a functional feature (right installation angle, that really improves downforce at higher speeds?), or just a cosmetic improvement?