Share 'Which tubeless rim? Alpha 340 or 355 29er?'

Hey...   I'm looking at building up a new wheelset for this upcoming season.  I've got the hubs and spokes sorted but I'm unsure on the rims.  Are the Stan's Alpha 340 rims strong enough or should I look for some 355 29er rims instead?   So far I've got this planned... Chris King Classic cross hubs - 32/32h Sapim CX-Rays    Also most of my training occurs on singletrack so I'm leaning towards the…