Similar progression path for me, with GW-BASIC in the middle.

However, I got a structured BASIC for the Speccy in a MicroHobby or Micromania magazine (cannot remember exactly), with screen editor, but naturally had the problem it would make the 48 KB memory size even smaller.

It would work better on the 128 KB models, but those lucky ones to own a 128 +3A could get hold of CP/M, with support for Mallard BASIC, CBASIC and BASCOM.