[Simon]

Submitting a dynamic, php-driven blog post to TGPs/LLs can be a problem for lots of reasons, including slowing things down as you mention.

What I do first is make a gallery template using a copy of a dynamic single post page, and then I strip out all of the unnecessary code that isn't needed for a submitted gallery. From there I save it as a regular old HTML template that I can use for galleries which will be submitted anywhere.

For each gallery I put a copy of that template into a new folder along with the graphics, thumbs, and full-size pictures needed for that gallery. Then I submit that new gallery URL instead of submitting the original blog post.

This does mean I have to take all of the information from the dynamically-created blog gallery post and put it into a copy of my plain HTML blog gallery template each time, but it's the only way I've found to wind up with a static page that matches the dynamic blog page.

(If you look at one of the blog galleries I've submitted to you and click the title of the post you can compare the submitted gallery to the dynamic blog post from which it was built.)

I'll let someone else answer the "how to create a thumbnail gallery blog post" in the first place since I don't use the built-in WordPress gallery features nor any of the plugins that have been created to help with that. I build my blog gallery posts manually, using Photoshop to crop and size thumbs in different ways for each post.

HTH a little.