MAN is the main 330 base. MAN pilots can be 330 only or MFF. You can bid for 321 SH only.
LGW is currently a single 330. Almost all will do MFF, MFF is default position. It is likely mostly SH in summer.
If you wish to change from default, bid based on seniority.
Smaller bases tend to tour more in Winter. Quite a few LH W patterns.
If LH 330 is your target, MAN is essential. With the current expansion it would come quickly. It is also the base least likely to suffer employment disruption should the tide turn against tcx.