Get your electrical problems sorted out before spending money on a battery (as long as your current one is working anyways). The lithium batteries will amplify any of your current issues, and will only make it more expensive to fix when the battery gets fried too. So if your R/R is bad, you'll find out when your battery starts smoking.
I know that we all have our opinions when it comes to the new lithium batteries, so here's mine: Don't waste your time and money with the a123 based batteries. They are all essentially the same thing in different packaging.
Shorai is the only company using their own prismatic cells. I've been happy with my Shorai, and have seen enough of the failures of the a123 based batteries to stay away from them. And don't buy a full spectrum battery. The owner of that company was a distributor for speedcell (one of, if not the first company that started making these a123 cell based batteries for motorsports) and started selling batteries under that name without permission. He eventually was sued (by the actual owner of the speedcell name who he was stealing from) and had to change the name to full spectrum.