Ports,
I have theater 4Pi's (one of the loudest models) connected to Adcom GFA 5400 (125 W/ch). I love it. Sure it is overkill for when you are just sitting in front of it casualy listening (it does run in class a for a few watts so ironically it sounds its best down low, & with 4Pi thats 99% of the time). I do like to feel it sometimes though(great for partying on the deck).There is much buzz over the circuit topology thing. Much of it is real. Where I find fault is when folks think your an idiot, or deaf, for not choosing the "better" one. I want SET tubes AND ss. I think these devices are great tools for different job (with a good bit of overlap). It can be so confusing when you see someone post about how awful sand amps are, then a week later they write a paragraph on how damaging subjective terms and hyped stereotypes are. The Pi forum has a lot of varied opinions, but you don't find a lot or doubletalk here. (you don't have to look far to find it though) We like what we like and I think you should start with the amp you have. You can't lose with killer headroom and a solid bottom octave. If you find the more intimate SET thing still beckons, there are great inexpensive kits abound. Keep both amps hooked up and put you speakers connection high on the cabinet so you can just reach over and change to the other speaker cable. I plan to build some bottlehead stuff this spring. I like '64 Chevy Impala and '97 Jetta GLX, I don't compare them, and I don't expect they drive the same. I like the difference.
I was worried about the big ss amp when I was building the Pi's. I thought the vol knob would be too touchy to adjust, and that it would blow me to the other end of the room. It's fine, so I still have yet to see a decent set of compatible equipment that couldn't be set up to sound great.
Thomas