DrNilesCrane: ... I was wondering, is the UESP version of Arena packaged with any "essential" mods that are important to making the game a more pleasant experience ...?
The UESP site has two links: To ArenaSetup.exe, which is Bethesda's Arena 1.07, bundled with an installation and configuration procedure for DOSBox 0.74 (I have never used ArenaSetup myself, as I always play Arena 1.06 and do the DOSBox configuration manually myself), created by someone called Ancestral Ghost. And to Arena106Setup.exe, which is Bethesda's Arena 1.06.
Arena 1.06: Floppy version.
Arena 1.07: CD version with voiceovers, graphically identical with the floppy version.
I was of the opinion that the two version are identical as far as gameplay is concerned, but dtgreene says she noticed a bug present in the (newer) CD version, so it may well be that 1.07 contains a few other changes, too.
I'm not aware of any Arena mods (unless you call the French translation mentioned on UESP a mod).
If you want the best possible visuals, make sure you set the details to max (ESC opens the options screen after you've started or loaded a game).