Hi,
when I first installed R197, SP8 was already available, so I haven't tried another combination. Here is howto install:
I already had R121 with uboot installed, so I didn't have to reinstall uboot. But that's what you should have to do first.
Make NAND backup.
Go into "emergency boot" by disconnecting all power sources + battery and holding "OK" for some time while plugging power back in.
Insert cf/sd card, go to /mnt/[card|cf]/ and run ./install .
Install SP8 (ipkg install)
Install what you need (I wrote a script to install things like rox, gnumeric, kopi/kapi, wpa_supplicant, firefox, wellenreiter, ...)
I use gnumeric, kapi/kopi, firefox and mplayer a lot and I found no real problems in R197, it's stable for me.
Cheers, Jan