Mariasplunge
I am using the Graham Slee Era IV gold preamp with good results. I am sure there is better but it fits in nicely with the performance level of the rest of my gear.
As far as the platforms go, I haven't experimented much with different ones. Basically I will build a platform and try it. So my comparisons have been basically with or without. My best results were for my sub. I built a platform around 6 inches think using 3/4 inch maple ply and filled it with about 75lbs of sand. It really tightened up and defined the bass. Much cleaner and deeper. I think it also helped to decouple the sub from the floor for the sake of my other components as I don't feel they are gettng as much resonance/vibration through the floor anymore. My speakers are towers and they are spiked to the floor so I can't offer knowledge on platforms for the speakers themselves. You mentioned the mapleshade catalog and I believe they make several different platforms but I have no experience with them.