Processor cores for FPGAs... any recommendations?

Hi all...
This isn't completely on-topic for this list, but I figured I'd ask
here since many of you do FPGA development on a daily basis -- some with MIPS processor cores, or other embedded CPUs.

This semester at university, I'm in a group working to produce a
FPGA-based device -- likely some NTP-synced alarm clock that scrolls reminder messages.

We've been looking around on OpenCores.org, and noticed the Plasma[1]
MIPS-1 processor core. We're also looking at JOP[2] and OpenRISC[3], but I'm liking the look of the Plasma core, since I'm already familiar with MIPS machines[4].

We've got use of a NIOS-2 Development kit[5], which is based on an
Altera Cyclone-II FPGA. It's hoped we can just load another processor core instead of the NIOS-2 softcore to drive the whole kit... Or would we be better served getting another development board? (Or just using the NIOS-2 softcore?)

Just wondering what peoples' experiences have been using this processor
core with Linux and/or µClinux? Are there other processor cores I could load onto a FPGA that people would recommend?

Stuart Longland (aka Redhatter)              .'''.
Gentoo Linux/MIPS Cobalt and Docs Developer  '.'` :
. . . . . . . . . . . . . . . . . . . . . .   .'.'
http://dev.gentoo.org/~redhatter             :.'

I haven't lost my mind...
  ...it's backed up on a tape somewhere.

Footnotes:
1. http://www.opencores.org/projects.cgi/web/mips/overview
2. http://www.opencores.org/projects.cgi/web/jop
3. http://www.opencores.org/projects.cgi/web/or1k
4. Although I'm very much a beginner ... my point is I don't know the
others _at all_ ... well, I know Java, but not JOP.
5. http://www.altera.com/products/devkits/altera/kit-Nios-2c35.html