I've seen some beauties here.
https://www.facebook.com/DDRGermanShepherds/timeline They are in my area but I am currently full here...Good luck.
I would go with a working line breeder that actually works and trains dogs. While a puppy is cute and dogs can be beautiful looking, the OP has stated they want a dog they can possibly do Schutzhund or IPO with. If that is the goal or even a desire, then the best bet is to look for breeders that actually do IPO with their dogs.
DDR or Czech dogs sound great from an advertising or "hype" on the internet. All that glitters is not gold and just because a dog has a few ancestors that were titled does not mean these breeders actually produce dogs that can work or are truly health dogs with excellent nerves and temperament. Again, people who are actually working dogs in IPO are not seeking these breeders out.
As mentioned previously, there is nothing wrong with wanting a certain type of dog because you like the looks of a dog. But, the OP wants to do IPO and may very well be disappointed by getting "the old school" Czech or DDR GSD that looks formidable but simply doesn't work well. I've done Schutzhund for years and actually work dogs. I have had GSD puppies that I have raised, trained and titled in IPO and other real world work venues. Puppies can be a crap shoot, I don't like to gamble so I select breeders that have proven their dogs can do the work that I want to do. I look at their results with their own dogs, not hyperbole on what the dogs "should" be able to do. Or what the dogs great grandfather did or accomplished. If a breeder only trains in their own back yard, has never titled a dog, but discusses how "real" their dogs are, those are red flags to me.
If you have an interest in doing Schutzhund or IPO then get a dog from a breeder where both parents are titled, have hips and elbows OFA'd to start. Ask the breeder if they have kept any dogs back from their breeding and actually worked and titled those dogs themselves. Ask how many dogs that they have bred have been titled in IPO? Ignore all the excuses of not being able to title a working dog, if that is what they claim they are breeding. Also, completely avoid any breeder that immediately knocks or bashes "sport" dogs. Because the next word out of their mouth will be the number of IPO titled dogs there are generations back. Then they will brag about the dog from 20-30 years ago in the pedigree that was titled in SchH or IPO.
It is very frustrating for someone to research and get a puppy with the hope of doing IPO only to invest months and maybe years to find out the dog just doesn't have the desire, ability, nerves or drive to do the work. I've seen this many times at IPO clubs. When you asked a serious, successful person doing the sport about the breeder they got the dog from, the response will be "Yea, their dogs don't work well, or you will never see any of their dogs titled."
The last 4 GSD's that I have raised from puppies have all excelled at IPO and LE work. All had good hips and elbows with strong, stable temperaments and high drive. I simply hedged my bets and went with proven breeders where both parents had been titled and high level sport dogs. I like serious, high drive male GSD's and social, high drive female GSD's. I've never had an issue finding a reputable breeder with GSD's capable of doing any type of work. With strong nerves, a good off switch and driven to work, and they have been "real" dogs as well.
Bottom line is that if you want a dog that can do IPO or anything else, go with a breeder that is successful in that venue with their own dogs. Not a breeder that imports a titled dog and then is unable to even title the dog again and just uses it for a back yard ATM machine. Avoid breeders that knock the sport that you want to do or make claims that they can do it. I would say the proof is in the pudding, simply show me that you can do it and not talk just talk about it. And I don't mean in their back yard,
there are a lot of 300 point IPO dogs in breeders back yards that would fall apart on a real trial field. Which is why they never leave their back yard.