Advice needed on the SMITH family

[charz]

Hi all,

I am in a dilemma,  i have a Smith family and someone has found me the baptism dates of the children and i know the father is a William Smith born abt 1787 place unknown married a Mary ?   married and children born in Bedminster Bristol

Would going the Bristol record office help me any further, could i find out who Mary is or where William is born  or is this an impossible task 

It takes about 3 hrs on train to get there and would make the trip if i thought it worthwhile, but not sure what to do? 

Anybody got any thoughts on this please.