How to implement this custom widget?

[Luca Cappa <luca cappa i-medlab com>]

Hello,
i would like to implement a widget like this:

+---------+
|Up Button|
+---------+
| Label1  |
+---------+
| Label2  |
+---------+
| Label3  |
+---------+
|         |
+---------+
|         |
+---------+
|         |
+---------+
|         |
+---------+
|         |
+---------+
| LabelM-1|
+---------+
| LabelM  |
+---------+
|Down-Button
+---------+


Where "Up" and "Down" are two buttons the scroll up and down the list 
composed of N labels, which visible at the same time are few than N, say 
for example M < N.

Which widgets should i use to implement that widget?

Thanks in advance,
Luca