Thanks, everyone for your help.
I already have a 7mm Nagler (and 9/13/20/31). I think I will try the 7 out and if seeing permits, I might go to the 3.5 Delos. But if seeing isn't very good with the 7mm, I won't buy the Delos.
Alan, the mirror is being made by Mike Lockwood, USA
I really appreciate your support.
Merry Christmas and I hope you are all getting more clear skies than we are in norther New Zealand. Two fine nights in the past month!!!!!
Kindest regards
Stephen