meerkat,
I think its time and others would agree... to dump your xp. MS is officially discontinuing support in April of this year. You'll be much happier on windows 7 or 8
Before deciding on which controller and RAID level to go with, think about how you will use your system. If for gaming, video, photo editing, I'd put my OS on SSD's on the intel controller in RAID0. You won't get faster performance. If your primary concern is redundancy and fault tolerance RAID1 fits that bill. But this RAID level comes with additional overhead, cost and small decrease in performance.
If your board only has two controllers, (example) Intel and Marvel, you'll need to pick one RAID level and controller and go with it. The Z87 controller only supports one RAID level or operate mode at a time. While it's possible to have more drives connected, each one is either included or excluded from the RAID, but you can't specify that disks on ports 0 and 1 will be RAID 1, and drives on ports 2 and 3 (or others) are another RAID. Before anyone jumps in and says RAID10 is 0+1, to the controller its still one array. It just gives the speed of 0 with the redundancy of 1
To achieve what you describe, you'll want to put another array on a secondary controller.
May I suggest that you use the intel controller for your boot drives (RAID0). These will be your SSD's, and use the secondary controller for your data - large drives RAID1. This will provide great boot and OS performance and balance when copying large amounts of data between your boot drives and data array. You data will have an additional level of protection being in RAID1 as each disk will have a complete image of your data.
You will get the same features and performance using either AHCI or RAID. Disk performance, TRIM and anything that is support by the drive and OS will be equal. Occasionally, a MB manufacturer will cut a corner and botch something with the way they chose to implement or support a feature, but in general you will not need to worry about this based on the scenario you described.
Most importantly. Back up your data. Implement a back up solution. Do not rely on any RAID level to protect against data loss.