Also to take into consideration the case. You are looking to use an SFX psu that's a standard size, boxey. Many of the Dell, Lenovo, Acer, HP, Compaq. Etc SFX mini towers come with proprietary psus, they are not boxey, but chopped up to avoid the motherboard, L shaped, fans at exhaust port etc. While most connections will work, some motherboards also use 6pin EPS, 5pin EPS etc.
I'll give Hamperking68 partial credit though, most ATX aftermarket psus will work on most aftermarket motherboards. It's really only the OEM proprietary psu's and mobo's that'll give a person fits.