I would look into a quality Barlow. like this 2" unit: https://www.amazon.com/Celestron-93436-Luminous-2-Inch-Barlow/dp/B00A2YFT00/ref=sr_1_13?keywords=barlow+lens&qid=1558440778&s=gateway&sr=8-13 , there may be better, but? It will double (in a matter of speaking) your eye piece collection. here is an article that may help understand barlows: https://telescopeschool.com/beginner/what-a-barlow-lens-means-and-does-for-a-telescope/