There used to be a good HoT Client floating around somewhere. I would recommend using the House of Thule client personally as it will give you pretty much all available zones, weapon graphics, NPC models that *most 99%* of servers have if they contain custom content.
As far as a server that fits your needs there are a few good ones out there. Going by the guidelines you've provided, one that would fit most of your wants/likes would be The Irreverent server. Contains live like events, accelerated exp, and soloable content, but allows for boxing. Another good server with custom content and allows boxing/accelerated exp would be Storm Haven, but its content is completely custom as far as zones to explore and quests to do. There is plenty to accomplish there as well.
Obviously try out several servers until you find one you enjoy. Most servers contain a website with some sort of information regarding the server and how it functions so don't be afraid to browse. There are several well put together and functioning servers with active developers so try out a couple before you make your decision as well. If you see a server you might think is interesting but isn't registered under the server list with a website, just log in and most keep a website in their MOTD when you first log in that you can check out. Good luck and welcome to the EQEmu world!
Wrath - Lead Admin and Owner of Enlightened Dark(Retired)
New server in the works!