I was almost going to be serious...then I read you're using an AeroRoast!?! Okay, okay, let me calm down...relaxing and breathing...okay....
First of all, premium beans are great on their own - you can actually enjoy them without blending. If you ARE going to blend, you need to understand the nuances of the beans and approach blending logically.
Topher made a good point about post-roast blending. Usually that makes good sense for the reason he mentioned. But the idea is to roast each type of bean to perfection and then blend. I'm not sure you have enough control over the roast to achieve that.
If you are serious about roasting, save your dimes and by a YM-2 or similar roaster. Do some "real" roasting and blending. I'm sure that is going to draw fire, no pun intended. But you'll find that if you use a good roaster and a couple of quality beans in a blend, you'll be really happy.
Simple is good. La Crema suggested Colombian and Brazilian...good choices. Heed the advice of those who have experience. Good luck. Happy roasting.