Saturn Forum - Saturn Enthusiasts Forums - best way for a SOHC rebuild?

Hey all. I just bought my first Saturn and it's a 95 SC1. The bad is i bought it with the head off.
The last owner said that his heater core went out and he fried the head gasket due to an overheat. Well it has been sitting with the head off for about a month and I'm kind of leery to just throw a new gasket on and call it good.
The car has 100k original miles and i figured i would just rebuild it while it's almost all apart anyhow. I'm just not sure how the best way to go about acquiring the parts would be. I'm really looking to squeeze every bit of MPG out of this engine and was curious about how similar the DOHC and SOHC lower ends are.
Mostly I'm wondering about whether i could use DOHC parts in my SOHC to increase performance or not.
Any help would be most appreciated. Thanks