Don't get me wrong, LiPo rocks!
It's just not a newbie thing...
If you like to tinker and are careful, Lipo, will give you years of wonderful power.
(The initial expense of charger and cables can be worth it, when you start adding parallel groups of the same series strings)
For newbies I suggest Ping LiFePo4 batteries (OR if you're tight on budget and have a month or so to wait, a VPower LiFePo4 battery (with charger, BMS)) is good too..
Nowadays, Lead just isn't really a viable option anymore because of weight to power ratio.