The mini3 is a great amp huh! The mini3 was actually my first diy project, built four weeks ago. It is great fun, you should give it a try!
As for IEMs, I'm not sure what is good for under $100, you can probably find the Westone UM2 for a little more cash, which are terrific sounding, and comfortable. When I tried them out, they sounded better than the super fi pros and were MUCH(10x) more comfortable. Now I have customs though, I'm in my own little world.
