Need Kt88s Genelex? or Shuguang?

What aspect are you trying to 'up-grade'. Tone? FR? Clarity?
For example, I use SED KT88's on one amp which may be a tad needy of some upper bass warmth and a little upper mid's and highs 'sparkle' but I use SED 6550's in another amp where I need tighter deep bass and linear tone thru the mid's and slightly soft highs.

I think it will help you in your search if you take a moment to define what you are looking for. There is no 'best sound' - its a matter of taste and synergy. FWIW the SED's are about as rugged and reliable as a family of tubes come.

The reissue KT88 Gold Lions may be just the ticket for you. I've read about the reliability issues. Sonically, as they have been described to me, they may be just the ticket. May be. I've not heard them in your amp. I would suggest that you would want to buy them from someone who carefully screens/tests the product and will stand behind them. In that regard, look up Jim McShane - he posts on Audio Asylum and has an outstanding reputation. He also has a history and you might discuss your situation with him before any purchase. Good luck........