Man!!!! Could have hit you up 2 years ago. Over in the USA, medium wave on Carrier-Current broadcasting is permissible license free. I was running 2W for my 610KHz station, but wanted a bit more beef. That, and my home brew and Panaxis gear was over 25 years old. So I went the way of the Greek made transmitters at http://www.pll.gr/
when that mono 20W carrier AM unit was $500.00USD's. Not a bad buy. I was always outbid on Radio Systems and older LPB, Inc., gear, so going the Greek way seemed the neat way to go. There is a PWM AM TX out there that's 10W, but sells for around $3,500.00USD's. If you can under cut that, it would be a better way to go since the Class A TX's are power hungry. Passing thoughts. Oh, BTW, Carrier-Current is where you couple to the power lines.