Hello, DSGRIM! Well, let me wish you congrats in advance!
Now, I'd go for the first option, because you already have a R4/Supercard combo which go pretty well together, so I'd dismiss the purchase of more flash carts.
My advice is to go for the Onyx DS Lite. I just got it last week (had a phat since Dec 05), and go for those accessories you mention. They are the prime best for the DS. Oh, and get a transparent hard case, because it'll protect the exterior of the DS from scratches and falls.