A write-up on an inline oxygenator was in an issue of BYO, but I don't remember which. Oxygenating with a stone in the wort would be a lot less hassle and probably net the same result if we're talking 5g of wort and not 7bbl.
Also, if you do oxygenate inline after your CFC make very sure the outflow temp is below 80F or so to avoid HSA (which may or may not be a problem depending on who you talk to, but why chance it
). I would put an aquarium thermometer on the inline oxygenator.