I would take the rear buckles if you have them and the boltsThe USPS offers all services to Hawaii. UPS is all second day or express air. The same goes for FedEx.
A spare tire will be a small fortune to ship. Anyone sending you seat belts and an IACV could easily fit them in a USPS Flat Rate Box for around $12. I haven't checked the condition of the rear seat belts in the '98 LSE I'm parting but if you're interested I coulf probably help you out. I ship Rover parts all over the world so Hawaii is easy.
Cheers,
Paul