Instead of the 15mm Plossl I recommend the 15mm Superview. See
https://www.bintel.com.au/product/bi...s-1-25-2-inch/
It represents excellent value and works well at 15mm and also when combined with your 2x Barlow will give you 7.5mm and 160x which is better for planets than the 133x from the 9mm alone. The apparent field of the 15 Superview is a nice 68 degrees. If you get one try it on Omega Centauri in your 'scope without the Barlow first then with.
The 15mm Plossl and 2x Parlow should work well to with 50 deg field.