SBS 2008 SQL Server 2008 Usage

I'm currently working on a project for a client - there are approximately 35 users, which will be using a SBS 2008 Premium server. Dual-core processor, 8GB RAM.

They do have a line of business application which will ultimately run on SQL 2008 standard - it is currently in the process of being converted into a MS SQL database by another party.

The size of the current database is 25GB with predicted growth of approx. 8GB per year.

I've been advised that the database is too big to run on a SBS 2008 Premium server, and have been advised to run a second Windows Server 2008 with SQL 2008 to 'host' the line of business application.

I have a couple of questions on this;

1) If one were to attempt to run SQL 2008 on the SBS 2008 box - what would be the pitfalls of this, and is it advisable for a database of this size to even attempt this?

2) If we join another Windows Server 2008 box to the existing domain and then install SQL 2008 to that box - what specification is suggested in terms of hardware for this box in order to achieve decent performance assuming 20 users max ?

Thanks for your help, have been reading various technet articles etc - however, hard to get a definitive answer on hardware specs -v- real world usability.