Something like this applied to your code:

DECLARE @sql_files_path varchar(100) = '\\SomeServer\Somepath\'

DECLARE @BulKInsert nvarchar(300)

SET @BulkInsert = '

BULK INSERT #fileContent FROM ''' + @sql_files_path + 'receipt_header.sql''

WITH (FIELDTERMINATOR ='' | '',ROWTERMINATOR ='' '');'

PRINT @BulKInsert

EXEC sp_executesql @BulkInsert;

Yes, this is a good place for a cursor. There's no way to import a set of files, they must be done one by one and a cursor is the way to go. Be sure to configure it correctly and don't leave the defaults.