Hello everyone! I am hoping to get a little assistance as to which ticket to buy for a connection to a separate ticket:

Already booked flight: LAX-TPE BR15 departing 0050a on Aug. 12

Now I need to book a flight *SFO-LAX* on Aug. 11 to connect to the flight above. I have the following two options:

(a) a UA flight departing 0813p and arriving 0959p. This gives me ~2h50m for connection. In this case United can through-check my bag to TPE so I don't re-check my luggage at LAX.

(b) a VX flight departing 0735p and arriving 0907p. This gives me ~3h40m for connection. Note however through-checking my bag is *not* an option here.

Which option should I go for? (b) has longer connection time but I might need extra time to re-check my bag, and (a) the other way around. Any suggestions are appreciated!