It depends on your particular boat; hounds are not in the same location.
For the Nacra Infusion the hound is in the same location as the Nacra 17:
http://nacra17.org/class-info/rigging-part-list/You have a few options on material:
1) 2.5mm Marlow D2 Max SK99
2) 3mm SK78 (any brand)
3) For a durable set you can use a line with a dyneema chafe sleeve:
http://www.apsltd.com/new-england-ropes-sts-wr2-dyneema-line.htmlIn 3mm that WR2 is a very nice and super durable trapeze line.
I generally float my ends so I have a few inches of travel adjustment at the base to get the handle right where I want it.