Goodtime surf at the gabba will hire if the boat is in there hire fleet- we bought second hand and were very happy with the saving.
we got 2 double spirit sit on top kayaks, these are a touring kayak complete with rudder and a whole lot easier for me and the wife to handle when the 2 under 10 kids are in the front and "helping"
They are reasonably light (I can man handle them onto the roofrack by myself) and track pretty well.
Me and the 9 year old boy traveled around Coochiemudlo Island in Moreton Bay
We had lined up to test a craft from cabulture cannot remember the name- maybe extreme- but they renigged on the Sat morning we had organised- wife had organised a hair appointment or something, but may be worth a call.
rosco canoes/ kayaks also hire but are at the expensive end of the market with there craft for sale.