Oh yeah, there are plenty of people using flat tappet cams.
Roller with the same duration numbers will still have the valve open at higher lifts for more of that duration due to the aggressive ramp profile. Over all lift may be the same but the amount of time the valve spends at higher lifts is greater with roller cams.
The cost is a lot more for a roller, but the damage done when the flat cam goes flat aint cheap either - not to say they will al go flat but there are lots of aftermarket flat cams wiping the #3e lobe.
Just approximating here:
flat tappet cam + lifters = $160
Roller:
cam = $325
lifters = $325 - make sure you get the newer lifters
need shorter push rods = $90
need stiffer springs, if you go with Beehive springs you will also need different locks and retainers, and then timing set. The gaskets are the same for both changes so that is an even wash but also part of the expense of the cam job - it all adds up.
You can count on about $1,000 for the roller
