Both Termidor SC (fipronil for termites) and Bora-Care will work, but Bora-Care is typically the better one to use for this situation. Termidor SC is not a wood treatment product, so for it to work you have to drill holes EXACTLY where the termites are and it has to touch the termites to work. If you miss where they are, it will not work. Also, Termidor SC does not really have any residual in the wood, so after you treat inside the wood with Termidor SC and it dries, that wood is exposed for future termite and beetle infestations.
Termidor: http://www.domyownpestcontrol.com/termidor-sc-p-184.html
Bora-Care is usually the preferred choice if most of the wood is exposed and it is raw wood you are treating, meaning it is not painted, stained, or sealed, it is just normal wood. Bora-Care is made only for wood, and you do not have to know exactly where the termites are for it to work which is a plus. Bora-Care is sprayed evenly over all exposed surfaces of the wood and actually penetrates through the entire piece of wood. When the termites in the wood try to consume the wood after it has been treated, they ingest the Bora-Care with the wood and die. No matter where they are in the wood the Bora-Care will find them as long as you treated the exposed wood that you can see. The other main benefit is that Bora-Care stays in the wood forever, so you will not have to worry about termites or beetles infesting the wood that you treated ever again.
Bora-Care: http://www.domyownpestcontrol.com/boracare-p-100.html
Termidor SC is a great choice for termite treatments. It lasts 10+ years in the soil if applied as directed. I have included a termite article below for additional information on treating around your structure. If you are going to be treating the wood in the crawlspace, we recommend that you apply Bora-Care if treating for drywood termites.