After reading your post it is very clear you're new to custom ROMs and kernels. Just be sure you have done some due diligence to be sure you haven't accidentally downloaded a ROM or kernel that wasn't developed for this phone.
A RUU cannot be flashed along with a ROM as the RUU will replace any ROM you flashed, such as Angry Bean as well as a host of other things so do not flash a RUU unless you basically want to return it back to the way it was originally or are doing it to fix something broken.
After giving that little warning anyway, performance and battery life are always going to be competing against each other. To maximize this phones performance, you will be sacrificing battery life so usually a balance of some kind is preferred.
ROMs will rarely increase signal strength on top of the stock radio and usually just do their best to get it back to what it would be normally. Some ROMs are not going to allow you to use 4G Wimax while some others will (usually newer JB/KK ROMs, and Sense 4 or newer ROMs will not have working Wimax).
Since you said you were running Angry Bean, you obviously have an unlocked bootloader (S-Off) and have downgraded it. In that case, I'll throw out a recommendation that you head over to the XDA forum and look through the ROMs posted there as most active developers have left this site.
A nice one to start off with is the
CM 10.2 - Hood Pope ROM developed by Dastin which will be Jelly Bean 4.3.1 and then flash the
Jelly Bean Mirage kernel, found on either this or XDA site. Great battery life, great performance, signal strength not bad.
