After istikharah the main point is the inclination of heart. If your heart is tending towards that proposal and there is no Shariah hindrance then it may be finalized with the advice of the family members. No decisive opinion can be established on the basis of dream. Also each dream carries various interpretations. Sometimes it is quite opposite to what it looks. However, you may follow your heart inclination after the istikharah.
Allah knows Best!
Darul Uloom Deoband