I don't do much visual work, but on the occasions that I do, i find I only use my Superview 15mm and a 40mm plossl. If I want to get in closer I use either my 2x TV Big Barlow or a 2.5x apo barlow.
If you want to try before you buy, you should try to get along to the Barambah Dark Sky Camp. It's on in only a couple of weeks time.
http://www.darkskycamp.org.au/photos.shtml
You'll get a chance to meet some other IISers, put some faces to the names.