Do you need pci, pci-E or usb? Want N300 or is 54Mbps OK?
RaLink, prior to being purchased by MediaTek, provided hardware specs to FreeBSD. For usb, pci and pci-E, anything RaLink is usually good. Mediatek is less so.
For pci-E, I also have good performance with rtl8188ce,
One caveat is the little usb nano adapters all look the same but have a multitude of different chipsets - Make sure you have an easy return if dmesg does not concur with what you tried to buy.
Some of the problems with "Branded" PCIe card is the manufacturers switch chipsets and use the same model number.
They do revisions and use completely different manufacturers for the wireless chipset using the same model number.
So take a gamble and find someone using a certain revision of the card known to work.
Don't ask me why, but I have found some of the older Mikrotik MiniPCI modules more powerful than MiniPCIe cards.
Personally I am using two purpose built FreeBSD Wireless Access Point's based on old Checkpoint firewall FW7520.
One has Ubiquity SR71-15 and one has Mikrotik R52HnD.
Both use an older AR9220 chipset but they kick ass. Totally commercial grade modules. They use MMCX connectors.
I really wonder if its a power thing. MiniPCie slot modules may be limited by the juice through the MiniPCIe connector.
I never looked up the power specs for each. I know Mikrotik advertises much higher numbers for their miniPCI cards.
So if PCI slot is an option consider that. You can buy wifi paddle cards for miniPCI too.
Look around for some miniPCI high-end modules in your country.
That may seem counter-intuitive but I can only relay my findings.
The only way I would reccomend RALink is on Arm boards with only USB interface to deal with.
The drivers pages for run(4) mentions this too:
The run driver does not support any of the 802.11n capabilities
The RT5370 mentioned earlier here has 2.4 and 5ghz. So that might fly.
On my BeagleBone!!!(USB ONLY)
Atheros is the FreeBSD wireless system. The developer is very active and has poured his hard work into our ath(4) driver.
The RALink uses a blackbox blob. Bahhhh.
Sorry I did read past his PCI card requirement. So I listed the killer Atheros radios, Here is the accompanying paddle card. https://www.startech.com/support/PCI2MPCIB
Note this one has no antenna holes. Ebay is loaded with these adapters with the antenna pigtails, just like the MiniPCIe versions.
For most of these cards I show they are commercial radios. They take a special connector on the wifi card called MMCX.
You will need MMCX to RP-SMA for your pigtails. Nothing special just different than what a laptop uses. Very rugged connector.
I can dig up some more part numbers if needed. Generally all the Mikrotik miniPCI cards on thier page here.
They all use Atheros.
Now there are some crappy Mini PCI Atheros wifi cards from laptops. AR5000, AR500x series. These predated the AR9XXX series.
I have the following Mikrotik modules- R52-Hnd, R2SHPn(The absolutely most powerful single channel card for point to point)and R52-nM for my PCI cards. All work on FreeBSD. I also have R11e-5HnD and R11e-2HPnD in the MiniPCIe format. All Atheros and working on FreeBSD. Some of those modules only offer 2.4ghz or 5ghz not both.
For Ubiquiti I have SR71-15 and SR71-3 miniPCI modules along with SR71-E in the MiniPCIe form factor.
The brands Compex and Winstron are also popular Atheros embedded manufacturers.
These are Atheros in rev A2 and rev A3 of the card: DLink DW552-A2 or DW552-A3. https://www.ebay.com/itm/322603257042
This is the A3 revision. Look at the sticker with Part Number.
It is only a 2.4ghz 802.11n card.
I just did a scan of ebay for ubiquiti and mikrotik modules and there are no deals I see. The Mikrotik site still has stuff for sale. https://www.ebay.com/itm/322389468511
This is that single channel card. No MIMO. The heatsink is so big it goes over the top of the card at a 90degree.
So you need a low profile miniPCI to PCI adapter card for it to clear. It is a beast. Not recommended except p2p.
Dual Channel or MIMO is better for most use cases. For home use the $15USD cards from Winstron is fine. https://www.ebay.com/itm/282607265114 https://wikidevi.com/wiki/Wistron_NeWeb_DNMA-83
So that is my homebrew recommendation. Gives you 802.11abgn and 2.4ghz and 5.0ghz coverage.
The MiniPCI to PCI adapter card is the only problem.
You must drill a 1/4" hole in the backplate or 2 holes for the Winstron 3xMIMO.
All of the MiniPCI to PCI adapters only have 1 RP-SMA antenna connector that I can find..
You will need a set of short lead pigtails too. Then you will have the best you can brew for PCI.