Well I did go roller on my 350 sbc 1st gen block motor. I had three past builds with a comp 292h and a crane engergizer 302h flat tappet cams and they where both really good in my little s-10.
My last built was a 383 and I decided to go back to 350 and went with first off a crane powermax roller with 234/242@50 duration 538/559 lift, but did not have the choppy idle I liked like the last two cams I had. So I went with a comp big mutha thumpr cam and they both do an awesome job for pulling off at idle clear over 6ooorpm plus and you can really feel the torque. I wish I never got the big mutha thumpr roller cam cause it has to much overlap for a racy idle. Comp says for street rods but I disagree with them.
The mutha thumpr is the biggest I would recommend if your going to want something with a rough idle. But the xtreme engery cam the 288hr is a better cam and will give a nice choppy idle but with not too much overlap. Too give you an example I just read a article in a hotrod magazine on comp cams top five best selling cams. The 292h wich is a 244/244@ 50 duration cam 501/501 lift made 2 hp less then the comp thumpr roller cam wich specs out at 227/241@ 50 with 513/ 498 lift. roller cams will always give you an average of 20 horse power over a similar grind of a flat tappet cam. But heads setup and other factors play in how much though too.
Torque is not much of a difference from what I have read anyways. The best benefit is you don't have to break in the cam and don't have to worry about if your going to loose a lobe or not with the zddp being low in oil that they make now. If you can get a chevy 1 piece rear main seal block with oem roller setup go with that. Retro fitting is way expensive. It cost me $500 plus just for lifters. If you go roller make sure you don't overcam your engine like I did just get something that is nice and if you want something of a choppy idle then go with a comp xtreme engergy series.
I wish the zddp additives was good in oil still. I would just use a flat tappet cam if I did not have to worry about losing my motor to wiped lobes. Do a search on chevyhighperformance.com and they have articles on roller conversion. good luck on what decide.