Any update as to whether the original poster has chosen which path he's going to take...???
Since I'm fairly new to reloading (little over a year). I'll voice my opinion in case a future reloader reads this thread. A little over a year ago, I was asking the same questions. I was given the same advise and had several private message from members that were concerned for my safety since I've never reloaded before. I did actually with what information was given to me. I bought several manuals and read until I had a good idea what it took to reload in a safe manor. For me, I was not happy with what was being offered in the kits. Looked at all of the reviews on youtube about all of the kits that were being offered to future reloaders. So, I started buying piece by piece. I ended up with a Lee Challenger Breech Lock Single Stage Press, Lee Dies, RCBS powder dispenser and a RCBS powder scale. Was very happy with what I bought. Plus, I bought everything else that it took to reload and clean the cases. Reloaded several and I mean several thousand rounds and ended up not being able to keep up with my shooting habits. I had the components, but, just could not keep ammo on hand. The more I reloaded, the mooooooore I shot. I "never planned" to shoot this much. Since, I had the means to reload my own ammo, the shooting spree took off like a virus. I couldn't control myself. I was having so much fun shooting and meeting new shooters like myself. I knew I had to do something about it. So, I started researching progressive loaders and to make this a short story. I ended up with a Dillon RL550B press set-up. I bought all of the quick change kits for all of my calibers. The only thing that I didn't buy from Dillon was the die's. I still use my Lee die's. Didn't have a problem with them on a single stage press and I still don't have a problem reloading with them on a progressive press. Believe me, once you have the means to reload, your shooting habits will increase. I have gotten so deep into reloading and shooting, that I'm in the process of building a range for myself. Heck, my wife now shoot's with me. She thinks her XD-9mm (I reload low recoil ammo for her) is the cats meow until I pull out one of my big grain magnum guns. Ok, I'm getting off-topic. Anyways, I wish I had done more research about single stage and progressive reloaders. The Dillon RL550B can be a single stage press, a turrent press and a progressive press. You just have to understand the basic's about reloading. Now, I still have my Lee press, which I use for decapping and use for load development. I can use the progressive but I find it fun and rather relaxing to use the single stage for decapping and R&D per load data. Plus, I don't want to get my progressive press dirty while decapping. I stainless steel wet tumble all of my brass and this gives me the chance to inspect all of my cases for defects. Plus I can wet tumble from a few 100 to several thousand cases (that includes rifle as well). I have several containers that I use in my process.
Ok, my advise, read, read and read as many manuals as you can. Then, watch youtube reviews and make your decision from there. Put it this way, if you go single stage first, and then feel your ready for a progressive press. No harm, cause you will find your way back to a single stage sometimes. Believe me, this hobby is very rewarding and verrrrry much addictive. Have fun and be safe...!!!