hi adrian
you need a t ring , if your barlow screws in that is a bonus but many barlows don't. if not get a 2" adapter for the t mount.
http://www.bintel.com.au/Astrophotog...oductview.aspx
http://www.bintel.com.au/Astrophotog...oductview.aspx
really it is for the planets, use video mode and RegiStax 6.
otherwise if you want deep sky you should probably go widefield as suggested below.
only a few small targets may work with super short exposures: eg, the homunculus nebula, ghost of jupiter the bug nebula, the saturn neb, any small bright planetary neb is your best chance.