Christian, i have no experience with Newman solid followers but i'd never buy the type that have a small bolt in the end for adjustment.
I'd go for one piece solid followers such as these from Ferriday --->
http://www.ferriday.co.uk/performance/solid_lifters.htm
Which you use shims with, but no risk of them adjusting them selves or the weak bolt adjuster breaking.
Just my opinions though