Cams for 318's

Read tons of pages here and there, but so much info and opinions I'm getting confused, especially for my application.

Have a 66 dart with a stock 318 (only have dual exhaust) 2 bbl carter and stock iron intake. Want to get more fun driving it but thinking of more of low end torque than high end RMP (Don´t think I'm going to exceed 5.000 RPM at all).

I'm planing a cam switch as a first upgrade, definitely want a 4bbl later but will have to wait at least a year. My dilemma is if there's a way of gaining power only with a cam switch? Have these in mind:

Summit Racing® Classic Cam and Lifter Kits SUM-K6900

Summit Racing® Cam Kits SUM-K50052

Leaning towards k50052 but don't know if I'm going to actually loose power. I'll be OK if I just pick up 5 HP and be ready for the later 4bbl swap.

Any advice?