If I buy this MD: Sony MZ-NHF800
http://www.amazon.co.uk/exec/obidos/ASIN/B0001ZN75E/202-6677391-8962221
http://www.planetminidisc.com/digital-upload-note.html

And this Mic: http://www.soundprofessionals.com/cgi-bin/gold/item/SP-SPSM-1

Will that give me a good quality when self recording (talking)?

And, most important, is it possible to transfer my self recordings from that device to my PC and my edit program - Vegas 4?

I have just order MD player Sony MZ-NH700, and microphone Sony ECM-DS70P.

So I will soon be able to tell how it work.

You can transfer from the device to edit in Vegas, I can't tell you how good or bad the combo will sound, because I don't know that microphone at all. The device looks pretty decent, and most MDs have a pretty good sound given the ATRACS compression format. I've used MD on many occasions, dumped it into Vegas, and carried very happily on.

Have you listened to the mic before? I would try to buy a mic that you've listened to or has lots of good reviews. Case in point:
Sony MS907/908 is a good M/S stereo microphone.
Sony 930 (stereo mic) is a total lemon- the camcorder mics on a Sony TRV110 are better. (It could be that particular mic is a lemon- in which case it makes sense to listen to it beforehand.)

2- You don't need stereo at all. However a stereo mic might be worth getting if it's better than the mono mics out there.

3- If you get a mic stand (or other stand), you can hang the microphone upside down and at an angle. This way you can get really close to the mic without popping p's or b's into it (talk and feel where the air goes- you don't want it in the mic). You greatly reduce background noise this way. You will also get more bass the closer you get- there may be some point where you're
getting too much (this is really a matter of taste).