I've been dealing with the subject for the last half of year and my opinion is that, if you want any results that are worth the money, try a custom solution, meaning have someone (or even yourself) hand-craft your website.
To put it short, the general steps to be followed are:
1. decide on the search terms you want to rank good for ... aim for more elaborate terms (and combinations) as they are easier to reach then generic one-word terms
2. clean up your site code (if it validates it's best), try to use semantic code (like H1 tags for page titles, H2 for subtitles, etc. instead of generic P with style) and try to make your page text (and headers) contain the search terms you are aiming for. Also provide the correct KEYWORDS and DESCRIPTION metatags (not mandatory, but useful)
3. Try to build incoming links from subject-related websites. Have someone make a review of your site or of one page on their blog, with a link to your page, etc. The more links the better.
4. The most important: stay away from "black-hat" SEO tricks (check Google submission rules for more details). While
You don't really need to submit your website to search engines ... if you have incoming links from heavily crawled sites, the spiders will reach your site as well. Not sure about Yahoo and MSN, but this works well with Google. The only place where you would need submission are web directories (colection of subject related websites). Yahoo features better the sites that are in their web directory, but IIRC the submission requires a fee.
Some guidelines can be found at:
http://www.google.com/webmasters/
http://www.4webmarketing.biz/searchengi ... erules.htm
If you need further details, send me a PM.