Edorr, yes the Ultraclocks and battery power (my supply is from BPT) make a big difference. As soon as Steve's got his new asyc available I'll upgrade to that, along with some Paul Hynes regulators.
I don't mind using my laptop, hence J River works fine. The laptop is small and silent. I tried feeding it via my ethernet network (still using J River and mapping the network drive), but it didn't sound as good as keeping everything local. The software geek in me says that shouldn't happen, but it did.
I may try Media Monkey. I've used it in the past to reorganize my file structure. Does their iPhone app also work on an iPad or iTouch? (Can you include a good link?)
I'm hopeful that at some point Sooloos will come down to a reasonable price, but until then I'm mixing and matching on my own.