>>953390I'm from New England USA, overall quite different than here! Yeah the built-in mics are good on pretty much all the stereo recorders these days. So good in fact that upgrading is a pretty big step because the built-in mics on the DR-05/H4N/DR-40/etc are already quite good.
As far as windmuffs go you really have to find the right one that fits. Rycote, Windtech, and Auray are the two brands I know are good that make muffs specifically to fit these recorders. For example, the Auray WRW-H4DR is the one designed to fit the DR-05. Check out the B&H website or Amazon because they're both good for matching-up the right accessories. You can find them on Gumtree or eBay *maybe* but just know you need the right one.