Any race/class combo is fine, as long as it’s from the Basic Rules or the PHB. The Multiverse is infinite, and your characters can be drawn from any place or time that you can make fit without adding additional rules, or by tweaking existing ones in very small ways. It’s perfectly okay to be an elf from a forest, a dwarf from a deep mine, or a regular human doing regular human things, but it’s also okay to go a little crazy with a concept. If you can make your halfling a floating eyeball, that eyeball is welcome in the game.
You can go as crazy as you’d like with your character backgrounds as you’d like as well – adapt what’s out there on the web or in the PHB to suit your dream. You’re not limited to a strict fantasy setting either. There will be a liberal application of science-fantasy in the setting, so if your spontaneous-casting sorcerer is actually a cyborg with implants, leave it on the page and we’ll figure it out. There’s going to be very little that’s too messy.
Most important to me is that the players cooperate with each other. I won’t limit alignments, but the party is inviolable, and I’m asking that party strife be kept to a minimum. Get weird.
Stats are 4d6, dropping the lowest die value. Stats are rolled in order. Alternately, stats can be rolled 3d6, and arranged as the player wishes. I would like it if we all used the same die roller, and this one seems very good in the several dozen test rolls I used. Please disregard total die averages of 3 or less, unless you want to keep them.
You can email me stats in some editable form that would be ideal, but if you can only list this stuff out, so long as I can copy/paste them onto the character page here, that will be fine, too.