Sounds like he'd be best off with something with overdrive. Either AOD or AODE (4R70W) are highly regarded, as is the 700R4 if you're not averse to putting bowtie parts in it.
4R70W with a Baumann controller is a great combo. The later models have the important upgrades. 4x4 model is easiest to work with. ZF adapter and crossmember with mods is good for Dana 20 or upgrade to Atlas.