The Black Krim we have commercially available in the West is actually a much modified variety of the original article from Crimea. I grew the original ones around 2005 and they had little resemblance to those sold nowadays. I can definetely understand why the plant needed some improvement as they are prone to stunted growth in the original form (hence overseeding is mandatory) but I think many seed companies have gone too far in their efforts, if they aren't just marketing generic dark tomatoes under the "Black Krim" label. Perhaps you could try an original Black Krim? They are still available through seed swapping circles and from sellers based in Eastern Europe.
Roma is actually a much improved San Marzano hybrid, probably one of the most improved ones as it almost eliminates the parent's vulnerability to Blossom End Rot (BER). There are actually dozens of San Marzano hybrids and "improved" varieties, such as Polyphemus and Scatolone, and they were all developed as sauce/drying tomatoes so they would fit the bill rather nicely.
One final piece of advice is to research what you are planting if you opt for heirlooms. There's one truly excellent sauce/drying cultivar called Principe Borghese but the big problem is it was originally developed for very particular growing conditions (volcanic soil, long spells of dry weather etc). I tried growing it here, where every day there's at least 40% chance of thunderstorms and the nearest (extinct) volcano is hundreds of miles away and while the plants grew to gigantic proportions and set a lot of tomatoes these struggled to ripen and were so bland as to be unsuited for everything bar perhaps decoration. Never again.
