I made all my battens from 1x4x16 Miratec. Miratec is a product like MDF but is for outside use. Lots of new houses are using it in the area. Miratec Link I'm happy with the Miratec so far. I had pieces lying in the mud for months that were still just as solid as new stock.
I cut them in half and the ripped them lengthwise, effectively quartering the 1x4x16s in to 1x2x8s. I even eased the edges on a router table. Ripped Miratec has a near knife edge otherwise. I envisioned using a nail at the top bottom and middle to secure the battens. However, I found that they needed to be secured more and ended up screwing them to the hardipanel with stainless trim screws in at 2' and 6' feet up the wall also (ie nails at 0, 4, 8 ft, screws at 2 and 6 feet). Here is my first batch going up.
Although my house is vertical siding all the way, I decided to use hardiplanks (lap siding) on the gables. I liked the look of the contrasting lines and it was easier to deal with so far off the ground. I didn't use any OSB on the gables either.
Conclusions from my experience: I'm very happy with the look of the building and the end result. The cost of the battens is quite high and I did not really think much of it until I added up how much miratec was required. The battens are very time consuming and you have to find a way to secure them when there isnt a stud behind them (OSB or not). I feel good about the structural integrity of the building. The let in bracing is there and wasn't so hard to add. The panels themselves drastically tightened up the building.
Having done it without OSB, I do think I'd put the OSB in now if I were to have to start over tomorrow. I think it would be better if the hardi products were supported by OSB. I had a lot of places on the edges where the nail blew out the edge of the panel. My battens cover this all up now. I wouldn't consider using the panels without battens. I also think the standard window and door casings are going to be proud of my drywall if I ever get around to it. Although I'm really happy with the board and batten look I achieved and it looks really good with the house, I'd also really lean towards doing the entire structure in hardiplanks over OSB if I were to do it over again. The battens and the panels are difficult to install. More pics:
Maximum altitude! Here I am finishing up the trim around the top louvre. Pump jacks are braced side to side and back and forth.