The inteliflo is more or less the direct replacement in terms of footprint for your existing pump. The superflo will work for you but if you upgrade the board in your automation panel to play nice nice with the inteliflo you will have a more capable system. In the end the inteliflo is slightly more efficient to run as well. Remember to check for rebates from the utility company for switching to a VS pump.
If I had the RS-4, I'd consider replacing the board as well. My difference it that I have the RS-8 which is a more capable board and when looking to incorporate my pool into my Home Automation I found that I'd have to spend the $280 on the Autelis not mater which board I had so I just did that. With the Autelis and the Plugin for my Vera Plus Home automation system I am able to do everything a more recent pool control board can do, like opening the Vera page on my phone, scrolling down to Pool Controls on the first page of the app then clicking Pool Day Party, Pool Night Party or Spa Mode, each doing different things. Day Party and Spa Mode does basically what the Day Party and Spa Mode on the Jandy One Touch pad does with the addition of Day Party turning on the fans in the patio area. Night Party does everything that Night Party on the Jandy One Touch does but in addition to the pool lights, it turns on the patio lights, gazebo lights and fans.
Back to pump replacement. I ended up going with the SuperFlo even though it pumps about 10% less gallons per minute because it could be easily incorporated into my system by adding a couple of dual z-wave relays to the Vera Plus giving me control over the 4 speed presets on the SuperFlow. If I went to the IntelliFlo, I would have had to not only replace the pool control board but get a new Autelis control board or have the f/w flashed on my current one, which the developer of the Autelis would charge a fee to do. The Autelis controls are programmed specifically for the control board you are trying to control and require different f/w to control the board.
In your case, you are not faced with this issue and have an older Jandy Board that cannot control as many relays which means it cannot control as much equipment. If I had this board I would have had to upgrade to incorporate into my Vera anyhow as it is so old that Autelis doesn't even make a control unit for it. For your condition I'd say go with the IntelliFlo and a new control board but that will be quite the capital outlay for sure.
If you look at the thread I linked above you will see that the pros on here share a whole lot of information on pump sizing and no matter where you go with this it is worth the read.
Good luck and report back
tju22003 because inquiring minds want to know!