Yep,IRD makes one,32 big cog.If you really want a 34 gear,you could get a mega-range and buy 1 cog,then do some gear swapping.That's what I used to do on my old touring bike before I changed to a freehub.

If you are actually going to tour with it,try to stay with 6 gears if you can on a freewheel.With 7 speed,you run a liitle more risk of bending an axle.

Just to muddy the waters a little more,they made a wide(130) and narrow(126) six speed freewheel.As long as you have non indexing shifters,you can run either one.