I can't really answer the CL question, but just want to remind you that with BoA it's almost always a HP. Choose wisely...
Well even if you ask for 3k on BOA it would still be 3x cl. I would try to get BOA to match discover.
with BOA i'd say shoot for the stars. Try to get them to match the Amex. they have twice within 4.5 months beat my current highest lines. My card was unsecured in june at 1.2K, with my highest line the paypal @ 2K (everything else was between 1 and 1.4K). In July, I asked for 3K online, wasn't instant. I called in the same day and they gave me the 3K. I have heard you can wait a few days if not instant and don't call, normally they will give you a cli still-sometimes less than what you asked for, sometimes you'll still get what you asked for. It seems tough to get outright denied for a cli from them if your credit isn't terrible or you haven't been just rackin up inquiries.
at the end of october, i went for 6K online and it was instantly approved. At this point i had a 5K and 4K line reporting, all the rest 3K and lower. Hard pull both times though. Was worth it to me.
Discover bumped to 8k. Boa requested 5k Sig and got it. Both hp
Amex 3x? Please ask for the 3x!!! it will counter, I probably would have started with them actually, if they 3x it, then wait a month for it to update then ask Discover and BofA to get in the game and move the limits a large amount!
With FIA (Bank of America) they will counter you so say 6000 and see what you get; I went from 1-5 and 2-7500. I feel like I should have asked for more, but oh well. The highest they saw when I got 7500 was 5200, so they should have no problem giving you 6000 or more. I had the accounts for about nine and ten months before requesting the increases. Discover went from 1-3 but that was an analyst ringing me offering an increase.
3 credit limit increase in a few days is freaking awesome...