Transfer / Bus rental Vancouver?

Hi everyone,

Since we got the majority of people coming from outside of Canada we're looking to bring their to our venue by bus, so that they don't have to struggle with transit.
I'm having a really hard time finding bus rentals that are okay with just at most an hour rental, since I only need them to bring everyone from downtown Vancouver to Grouse Mountain in the morning, people will leave at different times we're guessing so we don't have a transfer back.
I did find Vancouver Schoolbusses and I like it, the price is great too (I don't want it to cost me an arm and a leg, Schoolbusses are about 85 each and I'm hoping on something similar), but FH doesn't like it too much because he, and a lot of people in his family are really tall and wouldn't be comfortable in it.
Does anyone have any affordable suggestions? Or maybe other ideas? It'll probably be around 70 people (having to order two busses is fine)
Thanks!