Finding Zero Length Files

I'm trying to build a process within SSIS and running into a large number of road blocks. I could just drop out into T-SQL and code this entire thing, but I'm trying not to do that so that I can take advantage of the parallel processing pieces as well as learn a few things along the way.

Here's the overview of what I need to do on a daily basis:
1. FTP files to a local directory which I haven't already grabbed
2. Make a copy of the files into an archive directory
3. gunzip the files in my working directory
4. Remove any zero length files
5. For each file in the directory, run a data flow task
6. At the successful completion of the data import, log the imported filename into a table, along with the row count
7. If 6 is true, delete the file from the working directory

I gave up trying to get the FTP task to do #1 and I also gave up trying to get a script task written to do this. So, I wrote a stored procedure that will grab any files off an FTP site that are not already in my archive directory.

I figured out that the File System Task is incapable of handling wildcard characters to basically do "copy *.gz...". I could have done this in very little code within TSQL as well, but decided to use a for each loop to go 1 file at a time and use the file system task to copy the file.

I've already setup the for each loop with the execute process task to do the gunzip of each file in the directory. I also figured out how to suppress the pop up window as well as make it ignore any error messages. (Some of our files get an "unexpected eof" from gunzip, so that I know when we're done with the process, anything with a .gz extension had an error unzipping and needs to be kicked back to the provider.) I do have one issue with the fact that the execute process task leaves a copy of gzip.exe running in memory that leaves the last file locked and has to be killed manually.
Now, I'm to the zero length files issue. There isn't anything in the file system task to let me perform operations based on a file attribute. I can do this using TSQL by shelling out through xp_cmdshell and running a dir /-C, piping that to a file, BCP the file into a table, and then string parse the file names for everything with a length of 0 and then issue a delete command. I would really rather not do that. I'm fairly certain that I can do this in WMI, but I have no idea how to code that. Essentially, what I want to do is fire off a WMI query that pulls back a list of files in a given directory with a length of zero, hand that list to a for each loop, log each zero length file name into a table within SQL Server that it was processed with 0 records, then delete the file.

Two questions:
1. Anyone know how to get the Execute Process task to not leave the last instance of the exe running when it completes?
2. Anyone know how to get a list of zero length files from a specified directory to feed to a for each loop?