Where To Perform Validation On Flat Files?

Our ETL process involves some pre-load validation, and I'm wondering how best to implement it in SSIS.

Some details on my situation: I need to import 30 flat files with different data formats into 30 destination tables. In addition, these files share a common header and footer row format, and I need to validate these headers and footers before using the imported data downstream. (For example, the footer contains a record count, and fields in the header and footer should match some user variables.) My first approach was to write a Perl script that splits each file into three (header, data, and footer), but while that makes it easy to import the data section, it's more complicated to validate the header and footer and work them into the control flow. I think I'd also have to copy the same logic for all 30 data flows, which is less than ideal.

It looks like implementing this logic directly in SSIS is a little ugly (though that could be my lack of experience speaking). As I thought about this some more, I came up with a couple other solutions -- any critiques or comments?

1) Write a custom source adapter (which will probably contain the default flat file adapter) that knows how to validate my header and footer. I'd be able to read the file formats from an XML file, which might make my scripts more generic, and I might even be able to handle some custom data conversions more elegantly than I'm doing right now. (These files represent null numerics as whitespace rather than an empty field.)

2) Beef up the Perl splitter to validate the header and footer. If the cleanest approach is to say "assume that SSIS is only loading pre-validated data", this makes the problem entirely external.

Or am I entirely missing the mark here? Any thoughts?