"Am all for" is a phrase used to indicate support or agreement with something. If you're looking for synonyms for this phrase, one option is "in favor of." You could also use "supportive of," "backing," "championing," or "advocating for." Other options that convey a similar idea include "up for," "keen on," "enthusiastic about," or "committed to." Depending on the context, you could also use more specific terms such as "proponent," "ally," "cheerleader," or "endorser." When looking for synonyms, it's important to understand the nuances of each term and choose the one that best fits the intended meaning.