I have Edelbrock performer rpm heads (60229) and Performer rpm cam as well. I need to get rockers and was told I couldnt use my old ones which are rail mount type. What kind do I need to be looking for and any brand/type reccomendations would help TONS.
I don't know why you wouldn't be able to use the rail rockers, although it would be conterproductive, IMHO. The rail rockers have little "rails" that stick down from the valve tip side of the rocker arm. It's these rails that hold the rocker arm on top of the valve tip. The problem with that would be that it's more friction, and if your valve tips won't fit into the rails (in which case you would NOT be able to use them).
With virtually all aftermarket heads, you'll have screw in studs, which makes using guide plates a snap (and probably already on your heads). Guide plates hold the push rod in position, and THIS is what keeps roller rockers on top of the valve tips. You MUST use hardened push rods with guide plates ... I repeat MUST.
I would recommend some Crane hardened push rods and some Harland Sharpe roller rockers. They're a great rocker that won't break the bank (and what I'm running on my 289 in my '66).