Only thing about changing lifter brands is that there is "No Standard" in push rod cup height. Chances are you will need diff push rods too.
I personally like the 829 Comp Lifters, never had trouble, and run 750-800 lbs open pressure.
I just check them on a regular basis, and replace them after 250-300 pass's.
I cant comment on the Isky lifters.

[color:"red"]65 Hemi Belvedere coming soon [/color]
[color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]