Once my storage starts filling up I was planning on sata 3 drives for bulk storage.
Your talking about SATA 3Gb/s HDDs, right? If so, that's a good idea.
If you're talking about SSDs then it's a bad idea. SATA 3Gb/s SSDs are "old tech". You want to buy a SATA 6Gb/s SSD even if you're going to connect it to a SATA 3Gb/s port.