I do trade the bund, but I really don't know a good calendar available for free that has the Ger/Fra/Ita etc auctions. Ultimately, the Finanzagentur, Tresor and others do publish auction calendars, so you can try to compile your own (although quite a few issues are syndicated, so you need to be in the cash bond mkt to know what's going on). If you want to try something properly choppy and fun, you might also want to look at the LIFFE gilt futures, but that's living on the edge. I don't know enough about Eurostoxx and other equity indices to comment meaningfully.
HSI is an insane beast. GLOBEX futs are pretty thin overnight. The best stuff to trade around that time I think is Eurex instruments.