Your living in dream land if you think any euro 6 truck isn’t going to give some trouble , most are mechanically good , but it’s the emissions hardware software that usually give trouble , a euro 6 motor has a lot more complications than euro 5 ,at a budget of £15g you won’t find anything other than a Renault t with low mileage , and low mileage is key if you ask me , over 700k km you start running in ever lasting problems brakes discs turbo starter Apu units etc , unless you totally need euro 6 at 15g I’d go euro 5 it will always export and you won’t loose a fortune