If you bet SP in Arc with Brit bookies on internet...

ttt

industry sp

seems like these are allowing PMu bets:-http://www.oddschecker.com/horse-racing-betting/longchamp/15:15/pmu

Can't believe you are even asking that question Duncan - it's the bookmaking industry we're talking about...

but 4 of them are doing Pari-Mutuel SP aswell as their own odds, millhouse

As long as you ask for it, otherwise you are on at the manufactured SP, designed ONLY to put the margins in their favour, Duncan...