I have been presented with this issue a number of times. You are doing a split in the right place. I have done both RCA and XLR. I would recommend the highest quality of RCA you can afford. I know this is painful. I do not recommend adding any converters. Native single ended is very very likely to sound the best, certainly at 25’.
Your system is going to sound much better getting the chest out from in between your speakers. I suspect if you hang a really thick rug below the windows, that will greatly improve imaging. Tube traps in the corners would probably also significantly improve the sound. An area rug in front of speakers until nearly your listening chair. Little corner traps (cheap and innocuous.
Also, this gives you the option of using super short speaker cables… this is reported to me by some folks I really respect to slow a really big jump in performance. You have to use a really short, high quality speaker cable… 1.5’ or maybe two feet. It is supposed to really improve the presence of the system. Something I have wanted to try, but never have been able to.