Hiya Glenn. If it was me, starting from scratch, I'd go 15/18mm. There's plenty on the market and it seems to be the comer scale - big enough to see, but with a relatively small footprint. However, I've been up to my tallywhacker in 20mm stuff for going on 40 years. Let me know if you decide to go 1/72, I've got an unbuilt metric shedload of plastic for Pacific theater.