Advice for bookies

Hi guys,
Been a while since have been here, hope everyone is well.

I'm working with a massive & well established tipster site and am launching a few sport betting sites and was wondering if anyone can recommend
the best bookies that offer either good revenue share / wagershare ( if available with sports .. I'm not sure )

These sites are focused around horse racing & football.
Ideally they would also offer an API as well

Only want bookies that have had no reported issues of closing accounts / stealing customers please

I know it sounds like a pretty generic question that gets asked a lot however I only want to focus on reputable programs
and I have been out of the gambling sector for some time now.

Thanks in advance to everyone who chimes in with some well needed advice