Setting up RAID-1 on 2 unequal disks

[Foo JH]

Hi all,

I unfortunately have 2 uneuqally sized SATA disks to set up a mirrored 
shared folder: 80GB and 120GB. On the 120GB I plan to set up this way:

/temp        2GB (double the system memory)
/shared    80GB
/               38GB

I plan to mirror /shared onto the 80GB. It won't be bootable, but I can 
always mount it onto another FreeBSD machine.

I've read some articles on mirroring on non-equal disks, notably:
http://people.freebsd.org/~rse/mirror/

My question is: is there an easier way to do this? The example looks 
quiet daunting for a noobie FreeBSD admin like me.

Appreciate any feedback on this. Thanks.