Flat tappet to solid roller...

Isn't there something about running solid rollers on the street that involves periodic lifter rebuild/replacement?

Not that I've ever heard of. All the old cars ran solid cam's for years. There is periodic valve lash adjustment, usually every 3-5k miles. But everyone I know who runs solid roller has said even after 5k miles they have yet to find them out adjustment. They really aren't as maintenance intensive as we are lead to believe.