William-
Just be cause you workout alone, doesn't mean you can't bench press. If you avoid going to failure and fatique, you will be able to have an excellent bench press workout without the need of a spotter. The method you want to use is the modified repetition method, coined by Louie Simmons of Westside Barbell fame, and perhaps one of the very best powerlifting innovators. Do repetitions short of what your maximum ammount is, example
5 Reps with a 8 Repetition Load
6 Reps with a 10 Rep Load
8 Reps with a 12 rep load, etc.
Each session add some poundage and watch your strength and size increase rapidly on the bench press!
As for the Smith Machine, sometimes it has its place, but not for regular bench pressing, as it has minimal carry over to barbell bench.
I hope your bench training goes well!
-Andrew