Take one as a cohort with the Dragon Cohort
feat to lower its LA by 3. It will be two levels lower due to being a cohort, but that's a net gain (and could be improved with the Close Cohort
feat). Alternatively, see if you can somehow shuffle things around so that you gain a cohort and apply the benefits of the feat to yourself. If not, you may be able to designate the "master" as a familiar or something.
Either that or make it a Tome Tome dragon
EDIT: You could take Practiced Spellcaster