An observation... if you are running stock stamped steel rockers they are OK up to .5" lift or a bit more if you want them to last. A roller for a 493, even a mild one, is likley to have more lift than that. Even with hydraulic lifters a high performance cam should use adjustable rockers. Bottom line, if you go the roller route you will probably need new rockers.

If you want to keep it simple, another flat tappet may be the best. With good lifter bores which you have and good oil they last. I run Rotella T plus STP because it has enough zinc, is readily available and cost effective. There are lots of other oil solutions.

There are some additionl things you can do to make it even better. Lifters with a small EDM oil hole to the cam face are available from Hughes, "Howards Lifters" and others. Also, if you order the cam from Comp, you can have it nitride hardened for an extra fee.