I resolved this issue about 2 years ago, primarily b/c I have neither the time nor patience to play "seek and ye *may* find". I invested about $25 in a program called RadioTracker(.com). With recent updates, it really has become a hands-off process. Incidentally, this is not a sponsored post; the thing has saved me tons of $$, so I pass on the tip where I can as a completely satisfied customer. Win only, so far as I know. Essentially, the app monitors Internet radio, pulling only what you want. Here's a hands-on explanation of how it works.
Typically, I start the app just prior to going to bed. I focus on two options. One lets me pick a genre; the other lets me select individual artists. I tend to stick with the latter, since I get too many who-cares files via genre. The app includes a humoungous database. (If my artist is not in it, I can add anyway.) Inserting Artist-A causes a slew of similar artists to appear in a right-hand column. Double-clicking any one or more tosses the name(s) into my get-em list. I then go to bed.
When I get back to the associated directory, I find dozens to hundred+ of marvelously cut MP3s, just waiting for me to toss em into iTunes. I set it so my bitrate is at least 192, so it sounds pretty darn good, esp since I didn't have to "work" at pulling them.
There's a feature to dump them into iTunes, but I prefer to drag & drop what I want into the iTunes directory. I then use "iTunes Folder Watch" to easily have iTunes acknowledge their inclusion. Oh-- there is a built-in RadioTracker option to prevent duplicates, thankfully. That includes what you already have.
So how did I learn about this app? Grabbed a UK iPod-related zine from Barnes & Noble. Same thing with photography-- when I want to really learn, I skip US zines in favor of their UK counterparts. Our zines are too focused on ads; UK zines invariably offer MUCH more meat.
