You will find some threads elsewhere in this forum and in the Lounges forum about the two options you have, which are Aspire and Premium Plaza, and of the two Premium Plaza is the better (and typically more expensive). Both have alcohol via bar service rather the open bars in the BA lounges, but the food options are in a similar space to the Galleries Club / First lounge offering. Aspire is open to Priority Pass members so often gets full, Plaza Premium therefore is quieter.

Also consider the pimp-your-own-lounge option by finding a table in one of the various restaurants and ordering bite sized meals. The restaurants concerned won't mind.