It all depends upon how particular you are about audio recordings, and what exactly your budget is. There are those who would dispute this, but it's been my experience that the lower-end Shure mics are more appropriate for live work. Yes, you'll find it splattered all over the internet that Michael Jackson recorded one of his albums using one...but I would argue that his percussive, SFX voice wasn't that demanding of the mic he used.
Your wish to combine the use of the mic with acoustic guitar is an important one, because this instrument is just as demanding of a good mic as vocals are -- but for different reasons.
If you are fortunate and have tons of excellent outboard gear, you can perhaps get good audio recordings out of less-than-perfect mics. But a good-quality, albeit expensive mic, will make your job a whole lot easier, and will give you recordings you can really be proud of.
Another thing you should ask yourself is where the recordings are going, or what will they be used for. If it's just something you play around with for family or friends, then your choice will be different than if the recordings are destined as demos or something even more important.
You don't say what your budget is, but I suspect you need to consider increasing whatever you have in mind...by perhaps a large margin. Beware of the huge influx of Chinese mics on the market...all made by a single company but sold under different names. The value looks impressive at first glance, but they don't deliver.
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