I'm new to these parts, but I'm looking for some opinions...

I recently picked up $25 Raleigh Grand Prix from a local thrift store.
I don't have much experience with wrenching on bikes, but I bought it because I thought fixing it up seemed like it could be a fun winter project and if nothing else be an inexpensive bike to learn with.

From what I can tell (thanks to all the great info found here) its a '74 with all the original components (including cottered cranks). It seems to be in pretty decent shape too - I had to replace the chain and the tires/tubes were rotten, but otherwise it seems ok.

The biggest problem I've found is the non-driveside crank is very loose making it impossible to pedal efficiently (or safely). I would like to replace the crankset with cotterless and there's where I hit a wall...

The problem is I can't decide which direction to take this project. And I think I need to settle on something before I really begin to tackle any of this.
Originally I thought of doing a SS conversion into a commuter/zipping around town bike, but its pretty hilly where we live so I started considering getting some drop handlebars and keeping all 10 speeds.

I keep waffling so I'm just looking for any opinions or suggestions (or criticisms) of what I should do with this so I can move forward.

Thanks for the input.