Check out the 10 Gig Networking Primer for the best discussion of compatible ethernet cards.
Failing that, the way I normally handle this is to go to the FreeBSD man page, which typically lists compatible cards.
Included below are relevant bits from the manpage, followed by my comments at the end.
Code:
DESCRIPTION
The sfxge driver provides support for 10Gb Ethernet adapters based on
Solarflare SFC9000 family controllers. The driver supports jumbo frames,
transmit/receive checksum offload, TCP Segmentation Offload (TSO), Large
Receive Offload (LRO), VLAN checksum offload, VLAN TSO, and Receive Side
Scaling (RSS) using MSI-X interrupts.
Code:
hw.sfxge.stats_update_period_ms
Period in milliseconds to refresh interface statistics from
hardware. The accepted range is 0 to 65535, the default is 1000
(1 second). Use zero value to disable periodic statistics
update. Supported on SFN8xxx series adapters with firmware
v6.2.1.1033 and later and SFN5xxx and SFN6xxx series adapters.
SFN7xxx series adapters and SFN8xxx series with earlier firmware
use a fixed 1000 milliseconds statistics update period. The
period may also be changed after the driver is loaded using the
sysctl dev.sfxge.%d.stats_update_period_ms.
SUPPORT
For general information and support, go to the Solarflare support website
at: https://support.solarflare.com.
Solarflare was acquired by Xilinx a few years back so is basically out of business. Prior to that, the cards had a very good reputation as a relatively power efficient and not super expensive alternative 10G card along the lines of the Mellanox ConnectX cards; driver support was funded/supported by Solarflare.
Like various other cards, these are not known for optimal compatibility with FreeNAS/TrueNAS; the Chelsio are still first-choice with some of the Intels in a close second place. However, enough people have had enough good experiences with cards like the 5122F/6122F that I cautiously recommend them as a low cost 10G option. I used a bunch of them for years in our ESXi cluster and was very pleased with them. This is not to say that they are on the same level as the Chelsio's though.
I have no experience with the 7122F but I would expect it to work without issue.