Graduation depends on the bank and your history with that CC. BofA, for example is about 9-12 months with a great history. Others like Orchard may never graduate (only have seen one person here who knew someone who graduated with Orchard, but no postes here have graduated).
Some banks say you can't have more than one card with them where the first card you have is secured. For example, I had two concurrent 99/500 offers. I accepted both and was denied on the latter because I accepted the first. From experience, Orchard is the same way. But you can have multiple secured cards from multiple lenders.
If you were to only have secured prime-based cards (BofA, National City, Citi, CUs, etc), ideally, you'd have 2 different lenders at amounts as high as possible.
Your score and credit history does matter when apping for a secured card. I has denied a secured card from BofA before.
