Do you want white margins or white leaf centres or all white? And do you want ones that emerge white and stay white or is emerging yellow and turning white OK?
Check out Don Rawson's hosta lists. They aren't perfect, but they will give you some good ideas. You'll find them at
http://www.hostalists.org/
And the one listing hostas subject to drawstring effect lists the following:
'Brim Cup'
'Captain's Adventure'
'Carnival'
'Christmas Tree'
'Crème de Menthe'
'Crown Jewel'
'Dew Drop'
'Exotic Frances Williams'
'Fair Maiden'
'Frosted Mini-muffins'
'Hoosier Homecoming'
'Lollapalooza'
'Lunar Eclipse'
'May T. Watts'
'Northern Halo'
'Nutty Husband'
'Patriot'
'Saint Elmo's Fire'
'Silver Spray'
'Sugar Daddy'
'Whirling Dervish'
Mind you, I have 'Karin' and feel that it is occasionally affected (not on the list) and I have 'Patriot' (on the list) and have never seen any sign of drawstring effect. The severity of the drawstring will also vary with the kind of weather you have when they are emerging and will not be consistent.
