I like cryptostocks I have a ton of shares on there, all you are missing is more activity here to help drum up more volume. But I think its progressing nicely. And your site is not a mess like mpex and a lagfest like glbse. Only thing I can think of is to have each security give the option to add more than one currency they accept per share so they can receive btc ltc dvc if they choose to at whatever price they have set.
or even use api or somesuch to use vircurex thru crypto to exchange, so that the issuer can get the coin of choice and the purchaser can pay with whatever they have @ live rates