If the Si is in better condition I would get the Si. Simply because it is a DOHC and has rear disc brakes.
I think the only updates would have been airbag steering wheels, but Im not 100% sure.
The facelift of 1994
In 1994, the EG Civic saw some minor updates and changes, but the exterior remained much the same. In the UK, the EG civic gained Anti-Lock Brakes & Rear Brake Discs as standard, a larger 'one-piece' rear spoiler and colour coded front air ducts. The interior was changed from grey to a charcoal colour.