An inexpensive solution for capturing 1080i Uncompressed 8-bit 4:2:2 is to use a 4-bay external eSATA chassis. We use Firmtek’s (about $500). You have to also purchase a PCI-X card to connect to your system (about $120). The chassis doesnt come with drives so you populate them on your own (which tends to be cheaper anyway) but after you populate it and stripe the drives RAID 0 you can capture uncompressed 1080i 8bit 4:2:2. Another benefit is the drives are easily swappable so you can put your RAID 0 striped drives aside and use the chassis for other drives when switching between projects.
I haven’t tried 4:4:4 uncompressed nor 4:2:2 10bit yet but I’ve been told you can do it with two of these chassis and cards all striped together RAID 0.
This isn’t the best solution but it works and is much less expensive than most other setups I’ve looked at.