Person who share the bet slip , doesn't wish to share name of bookie . Cause if he will tell this next bets he will get harder to stake ( lower limits , faster odds fall down and etc. )
I would look for sites that provide odds for this series of events (there are aggregators that allow you to see the variations of any odds/any market) and from there I would decide where to play.
I don't think it's an exclusive odds/combo of this bookmaker, surely there will be other providers that allow this type of bets.
In general there are always several bookmakers that allow the same bet (exotic markets/events are created most often by well known sites, so this is not the case...)