I've worked in recording studios (session work), and tried my own home recordings.
I've talked to sound engineers a lot about this, and the unequivocal reply is that there is no point in spending a lot of money for home recording gear - best to buy the basics and go with them.
Some people spend in excess of 10,000 (UK pounds i mean) on home equipment - which seems like a lot, but it's just a huge waste of money, as the best home equipment is nowhere near the quality of studio equipment.
Prime example - microphones - home recording -the shure sm-58 - about £100; studio recording - top of the range neumann mic - £2300
And that's just the mic.
The last studio I was in had a Mackie desk worth about £500,000, running on radar (also a lot of money), plus all the usual suspects e.g. lexicon reverb unit, eventide harmonisers, antares pitch correctors etc etc
So - in a nutshell - go cheap with your home gear, as trying to capture the studio sound is almost impossible on a tight budget, and even if you do spend a fortune on home equipment, it will still be nowhere near the standards that can be achieved in a studio.
Either that or save your money and go into a studio.
Listen to some takagi masakatsu (e.g. the track 'girls') - that should show you that the greatest of gear isn't necessary - it is more about the creativity of the individual using the gear.
If you are looking to just get some ideas down, then just buy a half decent condenser mic and run it into your computer with a little soundcard (e.g. the alesis io2) into cubase, and that should be enough (cubase has reverb/compression etc).
I once took an old John Williams classical guitar CD and ran it through cubase (added reverb etc), and the sound was phenomenal.
If you are only wanting to record just the one part, and aren't multitracking, then (seriously) get a little dictaphone - preferably a digital one with a USB connection on it. This way you can archive your ideas, and refer to them at a later date. You could also add effects when your idea is on the computer if you used cubase, or an equivalent program (e.g. you could add some reverb, some compression, normalisation etc etc). This could be the modern equivalent of Beethoven and his notebooks.
PS I have some photos of some studios I have worked in somewhere on my computer - i'll try to find them to show you the average amount of gear the typical studio will have.