Emmasacha, I hope you have taken everything told you here, in the spirit in which it was meant. I'm sure you have evaluated your mare carefully, as to her strong and weak points. The stallion you have chosen is definitely not the correct stallion for her. You will be doubling up on some conformation problems. This, plus it is obvious that he passes along his weak points.
Faye has given you some excellent stallions to consider. If none of those appeal to you, there are plenty more in the UK. I really think you should rethink your choice. Hopefully, you have not yet booked to the stallion you showed.
If it were me, I'd consider breeding your mare to another of her breed, but I do understand your wishing for something a little more refined. So with that in mind, please do consider a more appropriate stud for your girl. I think you'll be glad you did in the end.