Nik, I think she's a very cute horse, and seems to be quiet and willing. I have to say I haven't seen too many horses like her in my local rescues. And as a starter... Why not? My qh has much worse confo and schooling 1st level at the moment (under the trainer as I can't ride). Plus (as mentioned) once schooled to 1st level you can always sell her to the good home and look for more advanced horse.
As for wintec, I've seen it to be great fit for some horses, and horrid fit for others (like mine). As with -any- saddle. When you'll look for the saddle just get 5-6 saddles from the consignment and saddle fitter out to find out which is the best. If it'll be wintec then that's what it is. :)
"Life isn't about waiting for the storm to pass: it's about learning to dance in the rain..."
"When we are no longer able to change a situation - we are challenged to change ourselves."
"How people treat you is their karma; how you react is yours."