I'm hearing people compare part one sasuke to part one gaara. You can't really do that since gaaras level now is muc more advanced than part one.
I don't see amatarasu working to be honest for the simple fact that gaara can most PROBABLY block it; even if he wasn't able to dodge it he has sand armour and as we saw in kage submit eton/amatarasu dosent mlt sand quick if not at all (if he does it turns to glass). Keeping in mind MS Sasuke gets exausted if he uses ammy so he won't be spamming it.
Close range tai is pretty much ineffective for the simple reason the sand sheild. If he peirces through it with chidori blade it doesn't reach him straight away. It will take some time (roughly 7 seconds) to actually reach gaara, in that time gaara would have countered. Gaaras sand control is much better and can certainly use moves like sand rain to baffle sasuke.
Not to mention he can go airborne which is a huge disadvantage for sasuke
MS sasuke and gaara wins mid diff.
EMS Sasuke... It could go either way sinbce gaara can go air bourne making arrows just a bit less effective.