G'day Marty,
Where are you doing your course? I've been up there a couple of times with the HG and there is some great flying sites at Gero and the local pilots are very friendly and love to help out newbies, definitely take your glider.
Just food for thought, the largest gathering of HGs during the year is at Shellys Beach at Albany from Xmas onwards for two weeks. If I was driving over I'd spend a week there then keep going to Marges for the wavesailing and up to Gero.
Here's a vid of Albany over Xmas where it's flyable most days and easy to clock up big hours fast, if anyone wants to go for a tandem flight it's the place to go;
I've never heard of a tandem powered flight with a harness like mine, that is the realm of trikes. You wouldn't want to be a light person with a powered harness on a tandem glider, you won't be able to turn it. I fly mine with a Moyes Sonic 190vg and I'm 90 kgs and there is not much power to spare, 125 kgs wouldn't get off the ground in one no matter what size the wing, they're only a 120 cc gokart engine that puts out a massive 14 hp.
This link
www.hanggliding.org/ is the best place to find out anything about hanggliding, besides your instructor

.
Your in for treat Marty.