May I add some additional explanations to why I suggested who I did?
Your mare being a W line also descends from F and this line split into 2 specific “genres” as-it-were - - a jumping line and a dressage line. Today, many people think of F as strictly dressage, but it’s really not true. Ferdinand is a core stallion who was emphatically jumping, his famous son, Wendekreis was a jumper but some of his kids did dressage too. Waldkonig descends from Flügeladjutant. Waldkonig’s own personal damline also descends direct from Frustra II. Intersting to note that Flugeladjutant damline was straight A. Autocrat brings in A and D, as well as the introduction of jumper blood from Lugano II - - who, by the way was sired by Der Lowe out of an A mare. Therefore your mare is basically a goodly mix of A, D, F.
I suspect that with such strong dressage lineage, to breed to a jumper, you are not going to get a pure jumper. Even if you bred to a jumper stallion, you are more likely going to get an improved dressage horse. Perhaps a hunter. And this can be a very, very good thing, because Donella, your mare’s grand-kids should be a marked improvement (dressage) over herself BECAUSE of her influx of jumping blood.
This is not to slap down some of the young stallions mentioned, but since you are switching breeding direction with this mare, and she is a raw maiden, I would not use an unproven young stallion like Bon Balou. You not only don’t know what she’ll throw, especially because you are radically changing her breeding direction and technically introducing a completely new blood. A breeder doing this is thinking of the future generations, not necessarily what is immediately born. It is technically impacting your future mareline.
However, the mention of Viva Voltaire is a very good option too - solid blood, proven mareline, proven stallion himself. I’m sure they have frozen available if you prefer. Viva has a great brain and passes that on to his kids. Good conformation, good pure movement for technical marks, stamps his kids well. He has a couple kids in training with Tom Dvorak. He also has a number of kids jumping. Viva has been pretty consistent with his foal inspections too. So, another interesting choice for you, because you could end up either/or both. He’s fairly proven to be very consistent.
Your change in direction is also why I suggested Corcovado as an option (there’s frozen available too, I think) was because even though he and his sire both were specifically Holstein JUMPER bred, it turned out that Coriander not only showed and won at GP Show jumping, but also GP dressage… simultaneously! Coriander also was noted to have extraordinary brains. And he gave these gifts to his kids, and CorCovado is no exception. Corcovado is gifted with very good movement, enough to perform top level dressage, but if you check his pedigree, he is jumper bred all the way. Some of his kids are jumping, some are performing at dressage. All in all, good size, conformation, work ethic, performance abilities and athletics. The mareline coming through Coriander is very well-proven and it’s the mareline you study the most. Corcovado’s own momma is dual bred.
I also suggested Canabis Z, Clinton and Lord Z, because you have a maiden mare and these horses are all proven producers at the top level of sport. They are all 3 approved Hanoverian. All 3 have good conformation. The first 2 are notable in their movement. All 3 have semen available in Canada because Team Nijhof delivers it to storage in Canada.
Canabis Z especially is noted for top quality conformation, not to mention a very balanced pedigree. He proves himself through his kids. Clinton has excellent conformation and movement and is, as everyone knows, a gifted jumper, having been to the Olympics and many of his kids compete at the top of the sport.
With the heavy W/F line in your mare, you do have to be concerned about monsters. None of the horses I mentioned should encourage the production of monsters - neither mentally or physically ;). If you’re really concerned, then look at Lord Z. He’s a proven competitor, proven sire with kids competing at the top of the sport, and he adds considerable blood - the Ladykiller, Cottage Son and Meteor are EXTREMELY valuable blood and highly sought for and Lord Z carries it all within his first 3 generations. He’s a highly blooded stallion which should be very suitable for mares who have a propensity to have heavy kids. You know your mare’s personality and you will need to decide if this much blood would be a good thing or not. Some people like their food labelled as 5 chili peppers. Some prefer only 1 chili pepper. 
Either way, it’s an interesting choice and I think you’re right to introduce jumper blood to this mare as you will find that the right jumper stallion enhances the DRESSAGE breeding program.
Good luck!
For comparison the same trainer started another daughter of this mare, by Indoctro, and she wasn’t nearly as easy. So I do have to give Contendro some credit, for sure.