Well traditional logic with a standalone is you buy what you local and preferred mapper uses. I'm not sure you'll get recommendations here as other than myself not sure who's using a standalone?
Also what you looking for? You're building a dedicated track car arn't you? In which case are you thinking to ditch all the ****ty Renault OEM junk and UCH etc then run new dials like some Stack? Or, are you planning on retaining full functionality via integrated CANbus etc? If so, then other than SC there isn't an integrated ECU with the CAN coding on the market yet. It's a decent ECU the Delta 800 used in the Clio application. But I can't recommend their mapping, looked at my map the other day and running up to 51 degrees ignition timing at part throttle at high rpm, that whole area of timing is bonkers and on a high compression build, no wonder chunks of my pistons are MIA! :@
Kazumz, tbh the problem with the Renault ECU is it's too clever like most recent OEM ECU's. You couldn't better it in a standalone in terms of running an engine for a multitude of environments and fuels etc, but the problem is if you tinker beyond the realms of normal then the adaptation tables generated in closed loop are applied globally as a % in open loop. You wouldn't gain anything on a stockish engine with a standalone vs a good map like RST for example. It's only really needed when you have cams with enough overlap to cause an unstable MAP signal, and therefore need to switch over to an ECU capable of running TPS as primary load. Of course having TPS (and proper MAP) allows ITB's or decent boost management also - again well beyond stock.
