I've pretty much run the entire spectrum of shifters over the years; downtube friction, downtube indexing, indexing barcons and 7, 8, 9 and 10-speed brifters. Given my choice I'd use nothing but brifters but, in their absence, I liked the barcons better than downtube shifters.
Barcons aren't as convenient as brifters but are better, IMHO, than dt shifters. You really can't get to them while standing but you can't with dt shifters either. I used them on drop bars and never had a problem with hitting them with my knees at any time. One possibility is to trim the ends of the handlebars so the overall length remains the same after the barcons are installed. i didn't do that but others recommend it.
If he were still in business, I'd recommend getting a set of Kelly Take-Offs. They are brackets that clamp under regular dropbar brake levers and mount downtube shifters right next to your hands. I have them on my rain bike and am very happy using them. They aren't the equal of brifters but as close as you can get without the expense.