T-SQL – Real of Decimal datatype?

Dear experts,

I have an SQL 2008R2 database with a filed in it which is now Money datatype. But it look I’ll need to store more than 4 digits and as you know it is limit to for example 0.2345, but now I should be able to write a value like 0.234567 (up to 10 digit depends of customer precision selected).

So my question is – what data type I should select in SQL ? Decimal or real or float? This table is expected to have milions of records in few years and will be heavy used.

This amount will be used for :
1) A lot of Sum over it
 2)Delete other Money value to this value and then and then multiple by this value – 10 times rather than 1)

I think for now to use Decimal – like (12,9)