Whats the highest racial or template charisma boost you can get for a +1 LA?

I’m currently working on a Sha’ir Gish character that will eventually PrC into Zhentarim Skymage(LoD) and I need to buff my charisma as much as possible. Skymage has a gimmick of giving you a paladin mount, or at least a close facially thereof, which can be any creature that’s a size larger than you and has no more hit die than your Skymage level + Charisma mod + 1. I already have Spark(Dragon Mag) for +2. I’m also considering Prestige Races (also Dragon) for another +1. Unseelie Fey is unfortunately banned so that’s not an option. Other than that just about anything official is allowed. I’d prefer to stay at or below LA +1 is possible. Some other options i considered were Athasian Human (also Dragon mag) +2 to two stats, Draconic Creature for +2 to strength, con, and charisma, and savage progression half fey. Spark was ruled to only work on PHB races and not variants like Athasian so that’s probably off the table, and it kind of negates the benefits of any +2 charisma LA 0 race like Spellscale and Savage Progression Aasimar.

I could use magic items like tomes eventually to raise it farther, but i can’t rely on temporary boosts like cloaks of charisma because if my charisma gets lowered, like taking the cloak off, my mount might rebell and attack or abandon me, and that’s not fun for anyone. I’d prefer human for story reasons in the setting and to open up Human paragon as an option for another +2 untyped bonus, though small races aren’t a bad choice either because that opens up a medium mount. I’m aiming for a Wyvern to be my first mount with a True dragon of some kind as my final. Mostly likely a 11-14 hit dice gold dragon for general power and the ability to turn into a smaller animal for easy transportation. Though if anyone want’s to make a better suggestion id be happy to hear it.