I don't believe any significantly larger profile currently exists.
There is talk (and hope) of a new 'almost full' profile encompassing MonoTouch, MonoDroid and .Net4.5 in the future.
But today, the PCL profiles are defined as small subsets of full .Net - and you have to use extension mechanisms like plugins, PCLContrib, etc if you want larger capabilities.
With that said, I've seen a lot of sophisticated and rich apps built using Profile 104.
If the current PCL profiles are not sufficient for you, then you can of course, write your code in non-PCL code - at the price of having to maintain separate projects per platform. Redth tackled his WshLst project using this approach: https://github.com/Redth/WshLst/