Sun Conure to be in a townhome that has thinner walls could pose a big problem. I had a ringneck which are as loud as sun conures (suns are maybe louder), and truth be told, they are LOUD when they flockcall. I could hear my parrot shouting from the building entrance, and the bird was on 5th floor, windows closed. That is how loud that bird was. I cannot imagine having such a loud bird where I live now, my neighbours would for sure complain.
While I do agree that suns are stunning, and truth be told I really wanted one so bad few years back until I learned how truly loud they are. While a happy well behaved bird won't shout often, there is no guarantee to it. Personally, if I were in your shoes, I'd pass on this one, I know I did.