McGeorge and toyotapartsdeal.com are my go to US-based parts suppliers. They will probably have the highest discount levels. They are both regular Toyota dealers running an online business.

For heavy parts, parts.toyota.com will list several dealers based on your zip code. You can select pickup or free shipping over $75. However, not all dealers offer the same discounts and some dealers offer no discounts. I think out-of-state dealers will not charge sales tax.

Partsouq out of the UAE is the hands down best supplier on price and delivery times. Even with international shipping costs, they come out ahead on many parts. However, I do not know how well supplied they are for the 4Runner because it's not sold worldwide. I use them for my Land Cruiser.