You may wish to consider a Brandon. Bill Paolini gave them high marks recently for showing nebular detail.

I tried a 24 Brandon in the 18" Starmaster on NGC 6946 the other night in average seeing/transparency conditions and was very pleased with its throughput and rendering of galactic core and arm detail; given the number of elements and the comparative tint and tone of the antireflective coatings, I'm looking forward to trying out the 16, 12 and 8mm as soon as I can.

My Supermonocentric lineup ends at 10mm, so the Brandons will fill that minimal-element void at an affordable price.

PS - I'm still not giving up the 7.5 Tak LE anytime soon.