Machine built sets are kind of iffy, even if you get somebody to tension them properly. If threadlocker is used, then there is a limited window for easy tensioning before it all sets. You need to do a few trail rides on the wheels and give them a hard time before handing them over to your wheel builder as this lets the spokes untwist and the wheel fall into its actual state of true.
On the rims, the sun rims will be plenty strong, if not a bit heavy. The rule of thumb is that sun rims flat spot and mavic rims crack. Certain rims are the 'gold standard'. The mavic EX721 is probably the best price/weight/toughness ratio rim on the planet. It can take a beating like few others. If your touring is on road, then look at saving a few grams with the XM719, which is basically the same rim as the 721 but in a slightly softer alloy. I use 719s on my Mountainbike and I am in the same weight range as you.
On spokes: straight gauge spokes are weaker than double butted as they tend to snap instead of give. You will be hard pressed to find a machine built set with anything other than generic straight gauge spokes. Wheelsmith or DT swiss are brands of reliability.
You will easily spend the money saved by buying machine built wheels on labour and broken spokes. Most wheel builders will provide the first retension for free, the best will never have a customer take them up on the offer.
There is little difference in strength between a hand built 32 or 36 spoke wheel if the builder is any good. There is a huge difference in the availability of 32h and 36h rims. All bike shops will have a decent selection of 32h off the shelf, but only specialist downhill/freeride stores will have a decent range of 36h. A lot of stores only do 36h by special order. I am prepared to deal with a tiny loss of strength in order to have convenience and security of replacement parts on the road.
Last edited by radical_edward; 04-15-06 at 01:03 AM.