i have found the tutors to be less than stellar in sui because of it's consistency
i would take out the hyppies for wretches because wretches wreck many many decks out there (eating squees and welder targets, tog ammo)
null rod could conceivably be mainboard because you're not running serious artifacts
side them out for masticores if you have to
even though it's an 'accepted' sideboard card in sui, i personally feel it's suboptimal because sui really doesn't have that much mana to spend on pinging creatures AND keep it alive
some people run unearth and skittering skirges in sui
you could try that
i play a variant using masks as a sidecombo
it helps quite a bit against aggro and makes life a bitch for control
