60/40 is probably ideal. I know we all want our kit to come out as good as possible, but it's usually better to stay with standard equipment.
Solder should only be thought of as a mechanical connection - it shouldn't ever be expected to conduct electricity. It's just there to hold everything in place.
There are a lot of upgrade parts that won't fit without modifying the Stereomour chassis-plate: my Vampire RCA jacks were too big, my Cardas binding-posts were 3mm too wide, my Woo Audio Teflon tube sockets needed the screw holes moved, my DACT attenuator needed its keyhole to be on the opposite side... Might be more...
Don't worry about trying to upgrade the wire used with the kit - it's really high-quality wire, and anything bigger won't work, since some holes have to fit four wires.
I, too, used the Mundorf silver/oil caps to wonderful effect. I just added some bypass-caps to the power supply last night and I didn't find it to make any noticeable difference, but I use a power-regenerator so I wasn't expecting much. I haven't installed those Triad chokes yet but the amp already sounds amazing so I'm not in a rush to try them.
Waiting is surely the hardest part, but boy is it worth it!
