I like my Whirly Pop just fine. It does a great job, and as you say, it gives you plenty of control since you can raise or lower your heat or move it off the burner to keep your temps in range. I just let it cool then wipe it out with a dry paper towel after each batch. I wash it only when accumulated grunge starts flaking off the underside of the lid.
The only thing I don't like about it is the small batch size. I'd prefer to do 3 or 4 pounds of coffee at a time, and freeze it in 1/2 pound quantities (in a pint mason jar) after 2 or 3 days of degassing. One of these days I'm going to buy an RK Drum and convert a barbeque grill to a coffee roaster. That should also help reduce the effects of wind, which as you said, can alter your timings from one day to the next. I try to roast when it's not windy, but that's not always possible.
I get all of my green beans from Sweet Marias. My favorite to date has been Guatemala Bourbon Finca San Diego Buena Vista. The 20 pounds I bought is nearly gone, and there is no more of it available to buy. At least, not from the most recent crop. Mexico Organic Chiapas Proish Coop was another I liked as an SO. Again, there is no more of it available. Panama Las Flores de Boquete was one that was not clean enough to suit me as an SO, but when I blended it with an Ethiopian Yirga Cheffe and a little Sumatra Tarbarita Peaberry, it made a great morning cup. El Salvador Santa Ana Naranjo made a great espresso. I roasted it Full City.
The only problem I find with Sweet Marias is that they get fairly small lots of usually exceptional coffee. Often by the time you find one you really like, they're sold out. So now when I see a new one that has a review that appeals to me, I order a pound and try it. If I like, it, I'll place a larger order of 5 to 20 pounds, depending on how I plan to use it.
I'm still relatively new to home roasting, so I wouldn't consider myself especially knowledgeable. But so far I have found that I prefer a clean cup, so I gravitate to South American coffees, which tend to be cleaner in profile than African or Indonesian coffees. However, I really love a good low-acid Sumatran for the rich body it provides, so long as it doesn't have a moldy character. Some do. And I like some Kenyan and Ethiopian coffees if they aren't overly floral. By and large, when I blend, the base will be South American, and I'll use small amounts of Indonesian or African coffees to round out the blend.