Finally got what I needed...
A Fujitsu-Siemens Scaleo JA desktop PC with an AMD 3800+ processor, 1 GB RAM, 410GB HDD and a 19" Wide-Screen LCD from Lenovo. Well it was supposed to have 410 GB (1x250 + 1x160 HDDs) but came with a sole 320GB hard drive. Oh well, that will be sorted out. I also bought an Asus Nvidia 7300GS graphics adapter with 256MB in-board for better graphics performance. Since I didn't aim for any high-end stuff, I got all this quite cheap. The PC is remarkably silent. The OS is Vista Basic. I had preferred XP though. I installed Spectravue and it ran without problems, though with no radio connected.
And I got my no 2 SDR-IQ together with the enclosure for no 1. The enclosures are excellent build quality; quite thick and heavy. Good rubber feet with friction. I like that. The antenna feedline coming up from below puts a lot of tension on the radio and a very light box with plastic feet is likely to slip. The picture shows the enclosures stacked though the upper box has nothing inside. So far!
Next: Taking it all to Kongsfjord and setting it up.