For general use - mirroring is great, you get twice the read throughput, but all writes happen twice so you get a small degradation in performance...
Striping will give you better write speed, but will mean that if one drive fails, the whole filesystem will go....
Personally, I see little use in striping, unless you are using very high I/O bandwidth, and even then, I would look at running both mirrored and striped, thus giving you both the throughput of striping, and the redundancy of mirroring (but you need more disks
)
If you just want to use both drives, and have all the space, I would have 2 filesystems, as if one drive fails, you only lose the one filesystem.
If you do wish to do both, you can either create a stripe, then mirror it ( 0+1) or create a mirror, then stripe across it (1+0) For redundancy, a 1+0 (also known as 10) is better, as you can lose 50% of the drives (so long as they ar not both sides of 1 mirror) , and the thing keeps going, whereas with 0+1, if you lose more than one drive, the whole thing dies... (IIRC)
HTH