Not sure about the oxfords, but I bought a pair of the Enfield boots as a winter/wet weather boot and went with the suggestion on the website, which was "if you're between sizes go up half a size". I am also a size 44 (UK10), but they only come in 43.5 and 44.5 so I went with the 44.5 and am pretty happy with the fit. My feet are about the same width as yours, and maybe about a half cm shorter, but there is enough room in the toes that you should be fine for length. I definitely wouldn't want to go down a size. You can always wear thicker socks or add an insole if the fit is a little big, but if it's too small there's not much you can do.
One thing I noticed though, and it probably depends a lot on your foot, is that they were a little stiff when new and rubbed on the tops of my feet where the captoe started. Now that they are broken in however they no longer rub and are extremely comfortable. I particularly like the rubber soles for walking in the wet/snow/slush too as they provide infinitely more grip than a leather sole.
One last thing -- don't expect exceptional quality. Don't get me wrong, they are still decent, but just not in the same league as the English made shoes I own. There were a couple slight flaws in the leather and stitching on my pair and the leather is not as nice as some of my other shoes. The flaws are minor though and don't bother me at all, and the leather is calfskin and will still take a nice polish. For the price, for a full leather (and leather lined) Goodyear welted boot I think they are pretty hard to beat.