Seeking guidance from Allah (istikharah) when proposing to a woman one intends to marry

Ayyub bin Khalid al-Ansari narrates from his father, from his grandfather, that the Messenger of Allah (peace and blessings be upon him) said: "Keep the marriage proposal hidden, then perform ablution (wudu) and perform it well, then pray as much as Allah has written for you, then praise and glorify your Lord and say: 'Allahumma innaka taqdiru wa la aqdiru, wa ta'lamu wa la a'lamu, wa anta 'allamul-ghuyub, fa-in ra'ayta li fi fulanah (he should name her by her name) khayran li fi dini wa dunyaya wa akhirati fa-qdurha li, wa in kana ghayruha khayran li fi dini wa dunyaya wa akhirati fa-qdurha li' (O Allah, You have power and I have no power, You know and I do not know, and You are the Knower of the unseen. If You see good for me in so-and-so (he should name her) with regard to my religion, my world and my Hereafter, then decree her for me; and if someone other than her is better for me with regard to my religion, my world and my Hereafter, then decree her for me)."
This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Anas (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) intended to marry a woman, so he sent a woman to look at her and said: "Smell her breath and look at her lower legs." That woman went to them, and they said: O Umm so-and-so, shall we not give you a morning meal? She said: I will only eat food that so-and-so (the girl) brings. The narrator said: She climbed up onto their ledge and looked at her lower legs, then said: Daughter, pick the lice out of my hair. So she began picking out the lice while that woman kept smelling her breath. Then she came and informed (the Prophet, peace and blessings be upon him).
This hadith is sahih (authentic) on the condition of Imam Muslim, but they (the two Shaykhs, Bukhari and Muslim) did not record it.