Those Sophia 6SN7s seem quite overpriced, you can get almost any NOS for that price.... including real Russian 1578, RCA 5692, etc. Also the 5u4g does not need to be that pricey either. I haven't tried 2a3s, but not sure they need to be that much either.
If your current amp has nice parts I would stick with it, as a $1k new amp cannot possibly have a lot of high quality parts in it, and if you start upgrading you will easily double the price.