Mikka,
the block is real good stuff. it looks exactly like your pic. it's a white solid block inside - a bit like candle wax. mine is by KTC.
i don't feel there is a substitute without a loss in taste. i use it in specific circumstances only ie base and in CK's CTM. i also have the coconut flour which i use for mains quite a lot (much more than block).
i think whatever u use would give u an idea (effectively it gives a coconut flavour at the end of the day). i know some don't like to use it - so leaving out is also an option.