A MBA that has formal, declared concentrations is rather rare in Spain. If you want to study finance and get a job in finance, then your best bet is to go to IESE or ESADE, which have traditional two-year MBAs. Otherwise take a masters in finance at IE, ESADE, EADA or EADE.

What are your thoughts on European university? They have specific concentrations but I've heard mixed things

I can't recommend that. If you want to find work, then you should attend a ranked, accredited university. If you don't care about work, but just want a quality education, then at least attend something with the legal status of a university, with the formal right to issue degrees in the country where you are studying. The European University is neither.

IESE or IE would be great choices given their consistent placements in the FT rankings.

For e-business specifically, look closely at IESE - it's got some relevant electives (including "Internet Enabling Strategies," which is delivered in NYC through the program's global component;) as well as "Starting Internet Businesses."

As an aside: you probably won't find a concentration in e-business at an accredited business school in Spain (or most of Europe, for that matter) - but it's not unreasonable to expect to supplement an MBA program's core curriculum with relevant marketing curriculum and other courses - this should be sufficient in most cases.