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Have a look at discountasp.net - they do various flavours of hosted m$ technologies including SQL Server if required at reasonable prices at both US and Euro locations.
I don't know much about Frontpage extensions sorry...but then if you're a .NET developer, you wouldn't be needing them anyway would you?
Crystaltech.com - good if you dont mind using a US provider. Frontpage extensions will always be an option with all Windows hosting providers i think but if you are using an app that requires them (i.e. Frontpage) then i'd strongly advise looking to change to something better (i.e. any other web application).