I've been shooting and loading for .243 for many years. I don't do a lot volume although I've managed to put 2500 rounds down my Rem 700 VLS in the last 3 years.
I started off using a friends Rock Chucker and RCBS dies. Loading back then was more about how much powder would fit in the case without blowing primers. Thankfully I lived through that ok. I now own a Lee anniversary kit and use the press, scale and priming tool regularly. I bought a set of Stoney point comparators to fit on my digital calipers for measuring the cases, bullets and loaded rounds. I also have a set of outside micrometers and an RCBS casemaster. Don't like the v block, you can see brass on it after checking cases and you have to hold the case on the block while measuring. Changing finger pressure changes the runout indicated. Think the concentricity guages with a case holder and ball bearing may be a better idea. I've transitioned from my RCBS full length dies to Redding competition neck dies with the carbide expander and titanium nitride bushing. Also use the competition bullet seater. You may also wish to invest in a quality digital scale. I bought a Dillon but after they changed from CED to Ohaus manufacture. I found the single post design of the new model to be less than accurate. I measured the same bullet over 100 times and got +- .5 gr. I got a new CED pocket scale from RSI and like it better. The same test was +-.1 gr. I use the digital to check my drops after trickling them on the Lee balance. My eyes aren't as good as they were and the balance doesn't have a mirrored scale to eliminate parallax error. I also bought a CED Millennium chronograph and recently the SW Products Pressure Trace. Both tools reveal things that I'd have never known otherwise but the chrono is the one I think necessary for long range shooting. The pressure trace is good for finding double pressure spikes from too slow a powder and checking optimum barrel timing. I'm not sure if OBT works yet. I use a Forester neck turner. It works ok but the mechanism that sets the depth has a lot of backlash and that makes it difficult to set properly. A K&M or Pumpkin neck turner may be a better idea. IF you can get a titanium nitride pilot do so. If you are concerned with concentricity, accuracy and all you WILL need to turn necks regardless of having a tight necked chamber or not just to get uniform thickness. Forming cases from .308 cases might not be a bad idea. Most .243 cases come short and most factory chambers are cut long. You mentioned having software already. I use RSI Shooting Lab to keep track of my reloads and Quickload for researching new ones.
If had money to buy new gadgets I'd get a hood press and the Wilson dies. I'd also look into getting a good borescope and a good ball micrometer.