Please provide more details about your captcha as all depends on method used.
Also I need to be sure that you really want to prevent scraping and you won't use solver for spamming, for that reason I can provide you a way to measure your captcha efficiency, after learning stage, for example for 1M generated images.
Why you've set PHP skill instead Python in required skill list?
Anyway, please decide, if you are looking for captcha evaluation for its strengthening - so I can help you, or if you would like to get solver to get rid of captcha - then you need to find someone else.