I do not know any database on mesoporous materials, SBA-15.

But, you can easily prepare SBA-15.

Actually, the structures are slightly changed depending on synthetic conditions. 

my problem isn´t the synthesis we are looking to make a SBA-15 theorical model for the study of interactions of dopped SBA-15 materials

Perhaps you can check this out

Langmuir. 2009 May 19;25(10):5802-13. doi: 10.1021/la801560e.

Modeling micelle-templated mesoporous material SBA-15: atomistic model and gas adsorption studies.

Bhattacharya S, Coasne B, Hung FR, Gubbins KE.

I do not think there are any database for mesoporous matherials. Though I am not 100% sure about this.

Mesoporous silicas are amorphous which means there are hardly any theoretical models exactly represent their structures, at least not local structures. Only the long term periodicity could be presented in a theoretical model, and you can find in some literatures or you can roughly build it.