thanks guys
you are right im trying to get as much range as possible. it sounds like it is desirable to have such short FL as 3mm available, but i wont get as much regular use out of it.
instead of $200 on a barlow and a short FL EP, the other practical option is $315 for a 1.25" Televue 8mm-24mm zoom. that would cover 53x - 159x. i could always later barlow the 8mm for 320x !
choosing EPs is harder than the scope itself!
cheers for the help
Mark