Hello Are there any Google strength tools out there ... basically what I am looking for is something to give a indications of how valuable putting my links on another persons website is. Putting together many factors to and spits out a number indicating how valuable the link is.
the best link strength tool is google search results itself. Cause apart from SERPs google keeps every other info a secret. The changes in your serp are the indicator of the value of your backlinking efforts. any other indicator is just hitting around the bush. And these changes occur within a week unlike what many people say months or years. So your backlinking efforts are rewarded much faster. Another factor u may use is indexing time, ie. the time needed for a newly published post to get indexed in google. The faster that occurs the stronger is your site's authority in google.
Google provides incomplete information, but there are a few interesting tools that can help you with that task. I would recommend SEOMoz and SEOBook tools.
I don't think there is a need for a tool. Most of them give you inacurate guess results. You can judge value of the link by looking at PR of the page, quality of the site, if the site is authority site for it keywords, if the link is relevant to your site and number of outgoing links on the website. This should give you good indication if it is worth getting link from the site.
You can make decisions about it seeing that website page rank, does google showing site links for that domain, there is a tool available on seomoz.org that will show you link authority for a website in the range from 0 to 100.
This tool gives a good 'indication' if thats what you are looking for. http://www.seo4experts.com/view/backlink_value_checker.php