ktm -
Not sure what you're looking for, but I get all the option scans I need by using Trade Prospector (along with equity and index futures information).
Option functions include stocks with over and under priced options, contracts with unusual activity, high premium calls/puts, etc. already preconfigured. Also other option tools and an option montage that calculates greeks, IV, TheoVal, etc. that uses the CBOE delayed or realtime quotes and a variety of built in strategy analyzers/scanners that work off the montage.
If you wanted some special analysis, you could try emailing them. If it's something with broad use that's not already available in the software they might add it. You can see if it will satisfy your needs at
http://www.trade-prospector.com
As far as data downloads, when I was looking for one a couple of years ago I never came up with one worth a darn. Most sources of bulk (i.e., all 100,000 or so contracts) are pretty dirty - option data seems to be much more problematic than equity data and the job of just keeping the option chain definitions seems to present most vendors with a lot of trouble (most of the RT data vendors for instance can't seem to keep it right consistently). The CBOE data is clean, but as you noted it's only available on an underlying by underlying basis.
So I guess one option would be to write a download program that would hit their server via HTTP with a request for each underlying you're interested in and download the related file and process each in turn. Would be pretty tedious though and I'm not even sure it's practical from an execution time standpoint.
You might be better off finding a program/service that can work for you and let them worry about data and option chain integrity.
Good luck.