Speaking from experience: you'll have no problem finding factory parts if you ever need 'em.
Over the last eight years I have mostly given away my factory items (suspension, some steering bits, extra D30/35 axles, etc), and sold some of the bigger ticket stuff (t-case, etc).
Now that I'm dropping that rig back to stock I'm having no trouble finding factory parts in really good condition.
I've been given a lot of the same kind of parts I've given away (mmm... Karma!), and have found lots of guys willing to trade up their stock stuff for my upgraded stuff + a bit of cash.
Be good to your 4x4 community, and your 4x4 community will be good to you.
Cheers!
Adam