My molecules are fairly large and aromatic. If I perform a simple fischer esterification, what are the chances of avoiding the formation of amide bonds?
I dont think fischer esterification will work. Better you have to protect amine and go with EDCI to activate acid and add your alcohol to get ester. Then you deprotect the amine.
Classic esterification procedure almost always works if you substrate does not have acid-sensitive groups, if it is stable in strong acidic conditions, and when there are no specific issues with the isolation of your desired product after the reaction. It is not the best procedure for all the substrates though, that's why we have so many other conditions developed for this reaction.
I would like to give you more specific (and more useful answer), but unfortunately, it is not possible without knowing the structure of you starting material.