Playing as Oscar, which gear

I want to do my next playthrough as the son of Oscar of Astora.
The elite knight armor and the Crest shield as gear are clear but then what else would you recommend in terms of being lore-friendly?
Which weapons would you see fit for the Knight besides his Astora straight sword?  Weapons with the divine auxiliary effect seem appropriate to me.
Which spells would somewhat be fitting for his lore?
What would be a suitable covenant?
Please tell me your thoughts. 

Elite knight.

Crest shield.

Astora straight sword.

Sunbro or Way of White. Way of white originate in Thorolund though.

Solair is from Astora, take some inspiration.

Ring of the evil eye is from Astora.

Perhaps a healing miracle or one of the offensive ones?

As a knight on a mission, perhaps one of the stoneplate rings, these could be from Balder though, but I suspect it means Astora, since most of known knight come from there.

I would also like a mace in off-hand, just to be equipped as a knight. A short bow for effective.

Go for faith build.

Also, I try to light as many bonfires and in the end, link the fire.

Truthfully you could go with any of the crest shields (Note they are all from Astoran Knights) Weapons with a divine auxiliary sound about right. You could probably use a morning star as a secondary weapon too. The divine auxiliary rule also means that you can replace the astoran straight sword with Silver Knight Sword at Anor Londo. As the above poster stated a bow perhaps would be good in the off hand though instead maybe I would suggest if you go for the sunbros cov to go for faith in order to get sunlight blade for your blade.

Also covenants: Sunlight Warriors, Way of the White, Darkmoon Blades, Princess Guard

Reason I am saying all of these they come across as chivalrous. Note you may say DMB's Chivalrous? In their head they are invading and punishing people whom have killed Gwynevere.

Sunlight blade comes from killing Gwyndolin and looting the chest.

The mace was a normal weapon to use, in order to crush helmets and armor.

I am aware of this - however it seems fitting to the Sunlight Warriors covenant therefore you can kill gwyndolin (For false impersonation of Gwynevere) in order to get the Miracle that is rightfully the one of your cov

Hmm, true, never thought of it that way...

It does not really belong to the covenant, as the description said he went to his father tomb, equaling that to grave robbery, something that goes against most knightly codes.

"Miracle wielded by Lord Gwyn's firstborn.

Boost right weapon with rays of Sun.

The power of sunlight, manifested as
lightning, is very effective against dragons.

When the eldest son was stripped of his
deific status, he left this on his father's
coffin, perhaps as a final farewell."

Many have theorycrafted that the firstborn is connected to the Sunlight Warriors as in a manner they are disciples to him (Firstborn/Gwyn).

I know that, but even so, he was an individual that put it there by choice.

A hypothetical scenario. Let's say you are the leader of a group.

When you die, your son puts his personal items there in order to remember you.

Is it right for the members of the group to plunder your grave?

Thank you for sharing your informed ideas Teh Kitten's Cat and TehInfamousAmos.

Really like the idea of a mace or morning star in the off-hand alternatively to the shield.
The Astora straight sword is right for the beginning, later maybe the Greatsword of Artorias or the Dragonslayer spear.
For projectiles the light crossbow seems a little more natural for a knight, the bow is for me more of the hunter-type weapon.
A upgraded Dragoncrest shield seems pretty interesting for higher soul levels.

For the magical side healing mircale is appealing, walk of peace.. you know what, I think I'll go for just miracles, no pyromancy and no sorcery. To narrow the choices down a bit the healing, sunlight and lightning spells feel kinda right/divine to me. So Petrus and the Sunbros it is.
Before I forget, a no-sin rule(no killing NPC's and no covernant breaking) would also make sense, since he's a knight sworn to a code of honor. 

@Teh Kitten's Cat
There is one thing I don't understand:
"Also, I try to light as many bonfires and in the end, link the fire."
Link the fire? 'Tis some Zelda pun? No, just jokin.
What does it mean and why should one do it?

Ah, I was thinking like this. Sacrificing yourself in the end and linking the flames mean that the age of fire would continue. Instead of dooming the world by abandoning and ruling as the dark lord, what is more noble? Sacrificing yourself to continue, if only temporary, the age of flame, the age of prosperity, or forcing death and darkness upon everyone?

Just use the sword of astora or a divine boosted weapon.  You can't buff either of them anyway.