I guess this depends on your viewing plans, but while a computer PCI card receiver may not be ideal for some as the only receiver, I'd have to recommend that anyone getting a 2nd receiver should consider a PCI card receiver. As mentioned in other threads,
Twinhan no longer sells the 1020a, but that can be found on Ebay for less that $50 I think. There are newer versions of the Twinhan PCI card, but I'm not sure of just how compatable they are. I think the 102g is pretty much similar to the 1020a, but I know of at least one application where it won't function where the 1020a will.
But the advantage of getting a PCI card receiver as your second receiver is that it can do
AC3 audio, it can do 4.2.2 video and do
HD video, although the HD requires a fast computer. It can also allow you to stream programming across a network to other computers. I do this all the time, ie I have my Twinhan downstairs in a Win2k server, and via a shareware VNC program, I can remotely tune satellite signals from my wireless laptop, and view the programming on the laptop. This requires using TSREADER on the server and VLC on the laptop.
The disadvantage of a PCI card is that it may be more complicated to get output to a TV, depending on what video card is in your computer. I initially was running the audio/video from my computer to my TV, but this was less than ideal, so I eventually picked up a ROKU HD1000, which allows me to view SD or HD (but not 4.2.2) directly on my TV. Unfortunately the Roku isn't being made anymore.