For video, you’ll likely use vesa mode which is fairly fast, unless you get a Geforce 7950 or older. ( supports even a few early Radeon X & older Intel video cards ).
What you really have to watch for is network, sound & sata controller.
For sound, there is HD audio but try not get the latest. Get something with a little older HD audio chip ( preferably out for 2 years ).
For network card, go with one that is popular ( on-board on many systems ). Realtek has good support. Mine is below & works very well.
There is ahci sata driver ( untested by myself so not sure how well it works ). If you go sata then try to get something with legacy support ( in the BIOS ) and is ahci. My sata controller is non-ahci but works with legacy sata mode in Haiku.
Intel & VIA motherboard chipsets are really well supported. Nvidia & SIS chipsets should work good too.
If you stick to little dated but popular sound & network cards/chipsets then you’re very likely to get supported hardware.
Also, once you decide on motherboard, search http://dev.haiku-os.org for open tickets regarding video, network, etc.