A: Flooring Vents Depend On Preference & Availability
Mitch this is a very popular and widely asked question. Vents (floor registers) look great built into your floor if it's hardwood, However, getting a flush mount vent isn't always the easiest thing. It depends on the wood species, width, height, brand of flooring, etc.
There are many companies that you can work with to get a vent made to match the particular flooring brand you have purchased. It is expensive and takes you delivering additional flooring for company to match. At times you can send them a sample and they can stain match the sample. A great company which makes fantastic vents is Wood Ventures (www.woodventures.com). You can work with most vent companies to deliver unfinished and pre-finished vents.
A drop in vent will be an easier choice. If you have carpet, tile, vinyl, or some other type of floor then drop in vents will be the vent needed. It also comes down to preference.