first of all sm58 isn't that miserable heheh.
but if you're recording with it and it sounds sorta muffled. and you're on a low budget to afford a condenser. then you have to make do with loads of EQing which may not help much.
indeed condensers pick up the high frequencies better, if you really need to get one thats low priced, the only brand that i can recommend (most ppl diss) is Behringer.
I bought Behringer C2 ($120 for 2 mics!) lately that's more for instrument mike up (drums/guitars), you might wanna check (price range) and compare with other brands.
or if not , go 2nd hand. someone (i believe his nickname is 3rdlogic or something) is selling a Rode NTK for only $400+. and thats a tube mic too. (I got it at $670 4 years ago). although that may be abit heavy duty in your opinion, in terms of pricing , but most of my recording sound changed drastically cos of that mic. of course you need to improve on mike up and mixing also la..
www.behringer.com.sg
www.rode.com.au
and as for your boss recorder it looks fine. if you know how to use that well, you'll know how to learn to use most other hard disk recorders well in future. I'm on a korg d888 recorder. I've been on PC DAWs for 8 years and i had a little trouble moving on to hard disk recorders heheh.
and the "hiss" of air surrounding is it loud? it sounds like your levels settings are wrong, like you wacked up too much gain, but your master levels are low or something. do check.
in case you're not sure about phantom power, yeah I googled your boss recorder, it supports phantom power.
recording vocals, if there's too much popping, change the mic position try not to mike straight at your mouth. cos the air-output causes the poppin'. maybe try mike up at the height of your chin ,but pointing diagonally upwards at your nose. (and don't go tilting your head down to sing at the mic, that defeats the purpose). otherwise get a popfilter, from sweelee, i'm using one that costs $40. or if you want a cheap alternative. get a Hanger-wire, bend it into a shape of a pop filter. take your mom/sis's stockings and wrap over it. DIY.
i don't know, it's not that important to have a dead room to me. but it's important that everyone gets a cup of shut the f*ck up when recording hehe.
cheers
20¢ worth