I ran across these 03 Sirius decals, and thought you might be interested in looking at them. Here is the link:
http://www.geocities.com/scaledesigns
I saw where you had checked out the NASCALS decals and weren't impressed with them. Understand that the Scale Design decals are also printed on an ALPS printer; they ARE NOT Slixx or Wetworks quality, nor do they profess to be. From what I have seen, these are your two options for the Spencer car, unless as you say, you get a graphics program and print your own decals. Realize, however, if you do not have access to a high-end screen printing system, you are not going to get the quality of a Slixx, Wetworks, or JWTBM - these guys have spent A LOT of money to have multiple runs of their decals printed. Not trying to shoot you down, just stating the facts. You can either go with one of these ( NASCALS or Scale Designs ) to build your car, or you can wait and hope that one of the big companies will decide to print the Sirius decals. I could be wrong, but I don't think I'd hold my breath on that. Like I said, not trying to shoot you down - just being realistic.
lowdog