To expand on what Droid is saying:
Druid Light only has Sunbeam and Sunburst, and while it possesses decent MCL increase (+5), it has significant issues dealing damage.
EG: Sunbeam + Sunburst + SLA Sunburst at best.
FVS Light has a smoother levelling curve but somehow less viable options overall, but Angel of Vengeance is sadly underperforming, lacking many of the options Cleric does. Their only good pure Light spell is Divine Wrath, with Divine Punishment as a secondary. Searing Light SLA is not enough to fill the gap. The archon is underperforming.
Sun Cleric is by far the best, with a Searing Light SLA at level 3 instead of level 20, only one less CL/MCL than FVS, with all of the options FVS gets plus Sunbeam, Sunburst, Sun Bolt, as well as a Sunbeam and Sunburst SLA.
With alignment though, you get two more options. Sadly, they don't really work well with Mantles.
Wild Mage Sorcerer deals decent alignment damage, has limited access to Light spells, but scales the same spellpower. They have a pretty good capstone though. Hammer/Strike/Channel Entropy is pretty solid, and does far more damage than Clerics do, but with less coverage.
Channel Entropy's D6+18/cl knocks Divine Wrath's d6+9/cl out of the water, especially since Channel Entropy is a SLA, has a 12 sec CD instead of Wrath's 20 second CD, and isn't delayed. It's an Acid Well SLA with a Will Save... the only reason it's not meta is because of A: Wild Mage Jank and B: Elemental Casters seriously have that much more support.
Dark Bargainer Warlock technically deals "high" alignment damage, with the mixture of Utterdark Blast, potentially the Light Imbue and Powers Pact letting you do 100% Alignment/Light damage. I'd value it as more powerful than Druid Light at the very minimum, although it's far less versatile and tends to fall off. I'm not sure how it compares to FVS: I'd rank it higher but that's just because I've not seen a caster FVS for quite some time.
For Race though, there's really not a good choice. Between Human for extra feats, or a +stat race for extra DC, Light doesn't really benefit from any race in particular. Sure, you could say Morninglord is probably ideal, but that tree is so hideously expensive and jank that it's not worth it.
I personally like Drow for Darkfire, which actually does quite a bit of damage (though even without MCL a d8 spell isn't that powerful at endgame). Faerie Fire SLA for breaking boxes easily.