After market for Hondas

I'm new to Hondas -- drove a Miata for the past ten years -- and now
have a 2006 Honda Accord coupe, with the v6 and the 6 speed.

Having experienced the plethora of after market parts for the Miata,
I'm wondering if anyone can recommend a source for after market items
for the Honda. I'd specifically like to change the shift knob, and
maybe spiff the interior up a little. I'd also like to do some minor,
do-it-yourself performance mods.

Where can I get parts to make my Honda even better?