Yes, for single input capture either the DeckLink Mini Recorder (video signals up to 1080p30/1080i60) or DeckLink Mini Recorder 4K (video signals up to 1080p60/2160p30) would work.
For capturing multiple SDI inputs the current options are:
- DeckLink Duo 2 - up to 4 SDI inputs at up to 1080p60 resolution
- DeckLink Quad 2 - up to 8 SDI inputs at up to 1080p60 resolution
- DeckLink 8K Pro - up to 4 SDI inputs at up to 2160p60 resolution
OBS Studio uses the common Blackmagic Desktop Video SDK so pretty much any of the DeckLink cards (or UltraStudio or Intensity devices) should work with it.
For the multi-channel capture devices, you typically need to configure how you want the multiple SDI connectors to be used using the Desktop Video setup utility (which is installed as part of the Desktop Video drivers). This is because it's possible to configure the multi-channel cards in various ways (for the DeckLink Duo, for example, it can operate as 4 input, 2 in/2 out, 4 output, and so on).