If you have found out about the boy and whether he has the right criteria of being your spouse which is faith and righteous actions coupled with compatibility with yourself, then I suppose it should be enough with duas and tawassul to the Ahl bait (a.s)
There is a form of istekhara that is authenticated in the Ahadith which is from Imam Jaffer Sadiq a.s also in Bihar al Anwar.
If this is done, then taken help from Allah, you will make the decision with your right mind.
This is done as.follows.
First remember the greatness of Allah and His power, then thank and praise Him and then recite salawat for the Holy Prophet and his pure progeny peace be on them and follow it by reciting this phrase
«انی اسئلك و انك عالم الغيب و الشهاده الرحمن و الرحيم و انت علام الغيوب استخير الله برحمه»
The meaning is,
I seek from you, and you are the knower of everything hidden and apparent, the All Merciful and the Ever Merciful, the knower of all secrets, I yearn for goodness from the All perfect Allah through His Mercy.
InshAllah you will get to know how much the boy can be suitable for you when you strongly feel the decision you want to make.