Welcome to the forum!
First point - full part numbers will help you get more accurate answers to your questions.
Your title mentions 1746, so I'm going to assume you're building up an SLC chassis. SLC controllers require RSLogix 500 Starter or higher to program. This software isn't cheap, and if you find it cheap, it's probably not legal.
There is a free version of RSLogix 500, with which you can program MicroLogix 1000 and MicroLogix 1100 controllers. If it were me, I'd spend my money on a MicroLogix 1100 rather than spending it on the software - then you've got a current-series processor, with onboard I/O, power supply and ethernet, and it'll probably cost you less than the software for the SLC.
If you have money burning a hole in your pocket, I'd suggest you bypass RSLogix 500 altogether. Get yourself a 1769-L16ER-BB1B Compact Logix (again, I/O, power supply and ethernet onboard) and a copy of Studio 5000. The new hardware/software is programmed quite differently to the old, and while it's beneficial to know both, the Compact/Control Logix series and Studio 5000/Logix Designer is the way of the future. Of course, a Compact Logix and Studio 5000 will NOT come cheap - but if you've got money to burn, that's where I'd be pointing you.