" ... if I fancy a bit more of the old in-and-outy, I'm better of with more of a dildo kind of affair?"
A longer dildo would be best for this. Probably a relatively smooth-surfaced one (without lots of swirls and ridges and bumps and stuff).
There's a great article about choosing anal toys here:
http://www.a-womans-touch.com/article/0/62/Getting_started_with_anal_sex_play_how_to_choose_anal_toys.html