The main club in Bristol is Bristol and West but their training groups have various locations all around the city outskirts so might not be suitable!
Is there one at the university on your list (thats not too far from you)? Needs to be Bristol Uni not UWE though.
Also if you in Temple Meads area you can do a lot worse than a run up and down the Bristol to Bath cycle path! The path starts arounf the back of the train station on St.Philips Road (I'm pretty sure its sign posted from that direction).
Another good run is out to the Portway or up on the downs, all pretty easy to find and relatively central 
The main track I know of is in Whitchurch - miles away sadly...