We have a large e-commerce site with over 90,000 SKUs and we currently hand make each of our html pages using basic html editors (frontpage, dreamweaver, etc). Adding and updating products is becoming an arduous task and we want to automate our web development.

I like using static html pages, as opposed to server generated dynamic pages, for SEO purposes. We don't necessarily need the server to be generating these pages on the fly so I was thinking maybe a custom CMS would be the answer. I don't like the url strings that dymanic pages generate.

What we want to do is create static html pages based on a predefined layout and we want to auto create html pages with title tags and buy buttons, etc. Ideally, I would like to be able to specify a keyword and have it automatically name the page with that keyword and add it as a title tag. Kind of the same way frontpage works when you create a page. ie: a page named "Colored Widgets" would be named colored_widgets.htm and the title tag would be "Colored Widgets".

Does anyone have any suggestions?

It sounds like you need a good quality shopping cart system like these...

http://www.pinnaclecart.com/
http://www.interspire.com/shoppingcart/
http://www.jshop.co.uk/
http://digishop.sumeffect.com

With regard to your concerns...

There is no difference between a static page and dynamically generated page - the HTML output is the same

All the carts I've mentioned support "SE friendly URL's", but even the parameter based URL's don't have any problems getting indexed.

BlueDreamer is right - there's no difference between HTML created in Notepad, FrontPage, and ASP.NET. It's all HTML. (Note, that's only true in the sense that my DNA and your DNA are both DNA.) GoogleBot doesn't attempt to differentiate between the two. The quality and cross compatibility of the coding styles would be seen as a legit reason to favor one over the other, but, search engine friendliness probably isn't (assuming both generate valid markup with a <title>, etc).

URLs can be generated in any format, even dynamically. Which may point to that "custom" CMS, but let me tell you why that's a bad idea.

A "custom" CMS means not off the shelf, but it also implies programmed specifically for you. And that's going to be hiddeously expensive. Modern day application programmers are lazy, so pay by the project, not the hour. Expect this to cost several thousand.