Rockauto is the place to go for most spares specific to a TJ plus they often have the choice to select a genuine Mopar part
if you know the part number googling that often brings up some options like
https://moparonlineparts.com/
the only genuine OEM part I have bought was a spare water pump that I used a few years back and a spare cam position oil pump drive assembly that I have not used, but bought because the 05-06 have trouble with these and now are almost impossibe to get except for after market. to date I havent used it.
there is also
https://www.jeepsareus.com/
https://www.morris4x4center.com/ they have diagrams with part numbers and options
https://midwestjeepwillys.com/
https://www.quadratec.com/
I've bought bits and pieces from all of the above over the years
other parts you can get local like DNA brake discs and Bendix pads, McKay radiator hoses. all have part numbers to suit our TJ Wranglers
I'm not sure how the GST works now with the purchase of overseas goods. I recently purchased a Super Bright Osram H4 light globe for my moto bike from an English auto light bulb specialist.
https://www.powerbulbs.com/ cheap as chips and no GST when it was delivered to me, so how it's collected buggered if I know