I need Help about installing a new Version of Android on my Xperia x10 mini pro

Hi to All! I bought a used xperia x10 mini pro U20I ..and i saw that the Android OS is very old..just 2.1..i thought that i could update it to ICS officially but today i discovered that this update is only for the xperia mini pro (without x10!!!)

.So now i think that i should install a rom..if i can.I tried many method only to root it.,..without success (superoneclick..z4root..nothing) So i ask 2 things..

1)Where can i find a simple guide..very simple, that explain me how to root this phone and install it a custom rom?

2) Which custom Rom (An Android 2.3..or 4.0?) should i install to have a good battery life, the possibility to install new app like viber and, very important, to have a stable phone that doesnt restart randomly? (i read that this happens with some roms).


THANKS IN ADVANCE FOR YOUR ANSWERS!

I Rooted the phone.So just 1 Q.Can you suggest me a Custom Rom..Stable, without bugs, that doesnt make the phone to reboot..or drains battery..and that is compatible with viber?


Thanks!