between BM-Decklink Mini RECORDER 4k or Blackmagic Design DeckLink Mini MONITOR 4K

hello. my name is fian.
first, i am sorry if someone have been ask before. like in this thread:
viewtopic.php?f=66&t=14504&p=49397&hilit=camera+feed+on+easy+worship&sid=97cb90156f756e2c3c88d9e0f108737e#p49397

but, me still confuse.

i want to build a computer, that EW can show my cameras.
i have two cameras now(SDI output), and an computer, and one mixer video (thar has HDMI and SDI output, and has monitor, so i can switch them)

the problem is, what should i buy,
BM-Decklink Mini RECORDER 4k or Blackmagic Design DeckLink Mini MONITOR 4K to live my cameras as feed?
thanks

Personally I would buy the cheapest one of the two.
You may also look at the Magewell & AJA driverless USB 3.0 solutions too.