Before considering... do you have time for grooming the dog also do you mind about the shed fur?
If not you should consider short fur dog... such as doberman (much more easier train) or rottweiler (need more training).
I am a huge fan of GSD ever since kid time.... but I got myself doberman because i do not have the time to groom the dog or clean up the fur everyday.

I meant easier to train compare to Rottweiler... Doberman and GSD are almost equally easy to train.
You can find many breeder out there. Cropped ears are done at 8 weeks which normally will be on buyer side.
Also the quality of crop is depends on the skill of vet (its also an art to get nice crop) and the owner also need to know how to care for the ears till it's healed and stood up.
I don't crop my dob's ears cause it looks nicer in big ears than lousy crop.
Normally cropped ears dob are either puppies unable to sold in time or good quality showline dob selected by breeder.

You can always pay higher for that to be done if you don't mind paying.

Since like budget not a problem for you.... why not import? min 10K

Boxer?? no no no....... they need a lot of exercise....

I am looking to import 1 European Dob in for breeding.....
Wanna import together? Expected price should be about 13-15K/puppy of 2 months old.. Good quality of course.
Parents of multiple show champion.

Ya, some how that seems to be a standard price across Europe.... and shipping is already more or around than 1000Euros for #3 box...
Unless is import from Indonesia or nearby country then can save a lot on shipping.
Definitely parents are multiple show champion...
Not sure about the price of GSD though... hahaha... not into that field....

Most protective dogs need some level of training to mix well with old people or kids.....
Unless you consider those least protective breed like Labrador or golden... yet still require some training....
Bare in mind, dog are still dogs regardless of breed.....
No person can give you a right answer.... even a trained dog can be bad dog if the owner do not know how to control it.

Why not consider smaller breed and non-sporting breed?
Since you are like first time owner, at least if you mistakenly train up a smaller breed puppy, the damage may not be big.
Bigger dog will have bigger damage if not done right.