Hello, Last 7+ years I working for developing boting/scraping software for bookmaker and poker thematics and have successful experience in this area (full automation, betting/playng without any human interaction). My specialisation ideally fit to Your requirements. Regarding Your circumstances, software that I can develop for You will allows following:
* login to Betfair user account
* enumerate races and horses accordingly your algoritm
* place bets automatically or monitor picked races and notify user for place bet on her own
The bot software will be provides as standalone windows desktop application with friendly user interface. If necessary i can provide source code too (C++, Qt Framework). Also I can integrate this bot into Your existing software if You have it.
Do not hesistate ask me any questions, because I'm "geek" in this area.