I dunno, kind of like the looks of it as is (except the bar tape). If I were itching to add something I would go with the best wheelset I could afford. It's something you can take from build to build so not a bike specific expense. Keep the originals and if you sell to upgrade frames just put them back on for the next buyer.

Plus a bar tape that matches the seat if that one is comfortable for you. The whole neon mismatchy thing seems dated to me - but that's a personal taste.