I liked Lauranz's post because that really said it well - we have to give up so much control in doing DE that it makes sense that if we have to replace ourselves, we would want to try to pick a donor who is most like us, if possible.
I think nurture is very important but I will differ a bit from other posters in that I think nature is also very important. Intelligence and musical ability are known to be heritable - BUT, that doesn't mean there are any guarantees. It just means you are stacking the deck in your favor when you choose a donor with certain traits.
It is very important for you to feel comfortable with your donor as feelings may very well resurface time and again not only during your pregnancy, but also as your child grows. Please don't get hung up on what you "should" feel if only you were a better person, bla bla bla. You don't need that kind of pressure after everything you have gone through.
I can tell you from personal experience that I am so thankful now that I was comfortable with my donor's traits. I had three different donors, and only got pregnant with the last one. The first donor was educated, compassionate, and while she didn't look like me, she had my coloring, sort of. The eggs didn't work but I have no doubt I'd have been comfortable with having children from her eggs.
The second donor was chosen out of desperation. She was not educated, could not write or spell, and honestly I cannot believe I even chose her to begin with, but like I said, I was desperate but won't bore you with the details of the circumstances at that time. Those eggs did not work either and now I am SO GLAD they didn't. I think I would be obsessed with fears if they had.
My third donor is like the first in that I feel very comfortable with what I know about her, college-graduate, intelligent though not a high achiever or a genius or even in possession of any extraordinary talents, just a nice person who can write well, is thoughtful and kind, is healthy, and comes from a highly educated family - that last part was good enough for me in terms of choosing intelligence genes. One of the most important things about her aside from being proven (which jumps to the top of the list when you've had two DE failures already!) is that she looked like my DH. Everyone in her family has brown hair and brown eyes, just like in DH's family. I assumed we would get brown hair/brown eyes. Well one twin did but the other twin is blonde and blue eyed! He is way too old for that to change now - this is his coloring. My DH even asked his family if anyone had blue eyes and no one could think of a single person going back three generations. Unless there is some new science out there that I am unaware of, I thought blue eyes were recessive and that both genetic parents needed to provide a blue eye allele in order for blue eyes to be expressed in the progeny. We have even gone so far as to wonder if the IVF clinic made a mistake, that is how unlikely it seems we would get a blonde haired blue eyed child from DH and this donor. So all that to say, go ahead and stack your deck in favor of what you want and don't be ashamed for wanting what you want, but just realize you might get something else anyway. As the saying goes, "Man plans and God laughs."