Silvia is a fine beast but it wont steam and brew at once.
The Sunbeam 6900 probably wont last as long as the Silvia but you can brew and steam at the same time. Infact its the only one in its price class that can.
The Rocky is a very good grinder and has all the guts from Rancilios MD40 commercial grinder.
BUT if you really want the twin boiler option you are looking at $$$$$. Contact any of the sponsors
But do invest in good grinder. (he says owning a Sunbeam EM0480 does the job but grind varies a bit sometimes)
Have fun looking