amplifiers

[tseligas]

I highly recommend from my personal experience and from other professionals a traditional metronome like this one:
http://www.musiciansfriend.com/accessori...-metronome
It is like looking at a conductor's hand and your brain understands the tempo much better than watching a small screen!

On the other hand ease of transportation the korg is a industry standard:
http://www.musiciansfriend.com/accessori...-metronome
You can find old versions!

And finally I would probably recommend out of all a metronome + a Tuner:
http://www.musiciansfriend.com/accessori...-metronome
Again look for used ones you can get an even better deal.

In this one you can do long notes exercises ..so you blow the note and see if you are in tune and you adjust your lips accordingly.. I will post an exercise about this!

I got all of the above :-) but if you had to choose get #3.