If I were having a custom Rodriguez built, it would have disc brake tabs and no canti posts.
Pretty much all tandem makers have moved to disc brakes now - the big ones (203mm) at that.
Back to OT, you can go either way really, it's largely a matter of personal preference. V-brake compatible (long cable pull) drop levers with V brakes, conventional (short cable pull) brake levers with cantis or conventional levers with V brakes with PS travel agents.
In a rush to get an order out, I bought some Cane Creek SCX-5 cantis (tektro oryx 992 clone, which were out of stock everywhere at the time), and they work as good as my best V brakes - really!
I also tried some Tektro CR720s - I could never get these to actually brake well. They had a great lever feel, felt like they clamped well, but the dang bike kept rolling along. I suspect hard pad compound, but I was unwilling to waste more time wrenching when I could be riding. Saved this evaluation for future.
I run Avid BB7 road discs on front of my LHT now (using campy veloce brifters). They beat both the Vees and cantis I've tried, especially in the rain, and work exactly like the popular, proven mountain BB7.
Disc brakes are unsurpassed for wet braking - there's just no question about this. If you believe differently, you must not have tried them. I pondered "the disc question" for years, then 2 separate but identical circumstance near-death experiences motivated the relatively expensive move to disc braking (rolling down a hill in pouring rain at 10mph, absolutely could not stop before intersection/traffic, had to "Fred Flintstone" it to finally stop a foot before lane).
If OP is looking for a good V brake, allow me to suggest Tektro 857s. Cheap, arms are ~1cm longer then Avid SD 3-5-7s. Very nice finish, weight-relieved in rear, they're clearly nicer looking than the Avids and cost less. The longer arms allow you to run 2" tires with 60mm SKS fenders spaced off for mud and still have adequate clearance. My Avid SD7s would scrub the top of the fender at the noodle holder mechanism, these don't. They brake pretty good. At $13 they're cheap enough to try even if you end up not liking them.
http://aebike.com/page.cfm?PageID=30...ils&sku=BR7417