T - unless you're willing to do the necessary auditions and then take a calculated risk, you may become paralyzed with indecision. Here's a way forward, taking into account your current finances: You say you can acquire a new amp right now -- so buy one! Listen to all your short list candidates (in as many environments/stores as possible); even if you can't hear them all with identical gear/conditions, try to level the playing field a bit by choosing to hear the different amps with speakers of similar type and size and driver complement, if not the same make.
Whatever you decide, the amp you take home will be used with your current speakers -- a great way to understand what the new amp can do, since you're so familiar with the old speakers. This experience will prove invaluable when you begin shopping for new speakers. And in the meantime, you will have enjoyed the sound of tubes, albeit with your current speakers. It's fine to have a vision of a complete system in your head. But it's no reason to defer ALL gratification when it's possible to begin putting some pieces in place now (the calculated risk part ;-) There is no evidence that putting together an entire system all at once yields better results! Often it doesn't, and there you are, with no plan B, because you'd been holding this specific vision in your head. Anyway, that's been my experience FWIW ;-)
