Not sure about concealing them mate but I am sure there would be some products out there that could - I am thinking men's make-up. Really depends on your view of it though and if you are comfortable wearing it.
I know for a fact that bio-oil has got a really good reputation after extended use. A lot of pregnant women use it for scars and stretch marks and swear by it. However, I haven't used it from personal experience.
Just thought it might be a cheaper and slightly more well known option than some of the more experimental products you mention above.