I forgot about this thread, nice to see some activity.
Peter, regarding rating the paper's speed, I did some careful experiments this year and found that with freshly mixed paper developer (Ilford's Universal paper developer) mixed at 1:15 and maintained at a temperature of 68f, I can rate the grade 2 Arista RC paper at an EI of 12.
Prior to this, I was apt to refresh a used batch of developer, and not be too careful as to its temperature (as in, toss the plastic container in the microwave for 30 seconds and let it go at that), and thus was rating the same paper at around an EI of 3. This was in my garage-based darkroom, where 9 months out of the year it's likely to be colder than room temperature.
Once I started my portable processing box project I had to be more consistent with developing, since I can't develop by inspection using this box, and thus had to eliminate some variables in the process, which was how I found the EI=12 rating with 68f fresh chemistry.Your mileage may vary.
I suppose you already figured out that you have to trim about 3mm off the long edges of 8x10 paper to get them to fit into 8x10 sheet film holders.
Good luck and hope to see some results.