I have a 2007 Scattante Comp all carbon frame from Perf Bike that needs some new hardware. Ok, All new hardware. I'm not super rich so I've got to make my $$ count. I'm looking at the PB site (and others from my local area) and knowing what makes a good set of components from the zillions of combinations is daunting at best. A few assumptions: I'd like to limit my search to Shimano parts - that's what the bike has now and short of a few flats, it's never let me down. The shifter's are Shimano 105's (2007 vintage) and I'm going to try to keep those as they work and feel good to me. So, I'd like to focus on a new crankset, cassette, chain and derailure. Assuming ~$500'ish.
One other thought. When I put my bike on my stand, it seems like there is a fair amount of "drag" just spinning the pedals. I'm assuming this is old components but... really have no idea.

Any help out there?

Thanks,