To make stereo recordings, you're not going to want a pair of shotguns. You'll likely find a lot more use out of a pair of small diaphragm cardioid condenser mics. Rode makes a matched pair at a decent price point. And of course, the Oktava MK012 is a very popular mic at a reasonable price as well.
Shotgun mics are super directional and are used to isolate one particular sound amongst a moderately noisy background, or to pick up a sound the 3 - 6 feet away from the microphone (depending on the type of shotgun). Typically, their off-axis response is quite terrible - this is because they are meant to "see" the source as specifically as possible, with a minimum of sound from other directions.
Basically, the long gun is just more directional, is all. I use it when I'm out on the street in the city, recording buskers or helping friends with their independent movie sounds. The longer the interference tube, the more directional the mic becomes but it also makes the mic unsuitable for many situations where reflection might be an issue, like indoors, corridors, alleyways, etc. You really have to be conscious of which way the mic is pointing, where the nearest walls are and where the noise that you're trying to eliminate is coming from. I find the short gun gets a lot more use and often times, my SDCs get even more use still. If you plan to get serious about field recording, then you'll definitely need both a pair of SDCs and a shotgun mic... but I'd recommend starting off with the SDCs, if you don't have some already. They'll get you out there and capturing all sorts of stuff both in stereo and in mono and you'll start to learn which sources you'd like to use a more directional microphone on.
The "no wind" thing is crazy. It's a field recorder's worst enemy and you'll be fighting it all day, every day. Even a slight breeze inside a building from an air conditioner can ruin an otherwise decent recording. Wind protection is an absolute necessity and it is not cheap. A Rycote shotgun windscreen will cost you about $200 for the low end model. To get a blimp on a pistol grip, you're looking at like $600 - and these costs do not include the microphone, btw.
Plan your budget well and buy what is most important first. To start, I'd recommend a pair of SDCs and windscreens for them, a stereo bar to mount them on, shockmounts of some kind, if you intend to walk around with your mics while recording, a stand of your choosing, a great set of circumaural headphones, cabling and a waterproof bag to carry your recording device and all the toys.
Field recording is great fun, but it's certainly not cheap. It can also be crazy frustrating and rewarding. I look forward to hearing your captures!
