What's it for (I ask again)?
Voltages are normally measured as RMS. The second guess would be peak. If you mean peak to peak, you need to say so.
You're telling us the peak output voltage is 10V. and you want a peak output voltage of 50V. In that case a +/-60V supply may be OK.
But what are you driving?
Voltage gain means that the output voltage is greater (in this case 5 times) more than the input voltage.
Many amplifiers are not voltage amplifiers. For example if your amplifier was to be used to drive an 8 ohm speaker, it would be a 150W RMS amplifier (approx).
Now, I can bet that your signal generator probably has an output power measured in milliwatts -- I'll guess it's about 40mW, so the amplifier you want may have a power gain of (a least!) 3700 -- possibly much, much higher.
And THAT is the reason I need to ask what sort of gain do you want and what is it going to be used for.
edit: There are other reasons too -- are you concerned with distortion? If so, how much?