i would never buy a hardware synthesizer for casual usage in 2013. just buy a midi keyboard and use VST synths, they are VERY GOOD these days, including some of the free/super cheap ones. also, this means you'll have to get a sound card with a midi input, which the apogee one doesn't have, so in that case it's not suitable for your needs (this is why i need you to specify what you want to do before i can recommend an interface).
for cheaper drum software you have a couple options:
addictive drums – this is what i use. it can sound really good but beware that literally all of the presets are garbage, so you'll have to dial in your own sound. really great samples though. there is a decent metal expansion for modern metal sounds, i would also recommend the "retro" expansion which has real good sounding huge 70's type kits
ezdrummer – this is prob the most common one, it's good, but it affords somewhat lesser flexibility than AD as the drums are already pre-processed, while they are fairly raw in AD. this means you'll get a better sound out of the box but if you don't like the out-of-the-box sounds, you're more or less shit outta luck
big fucking drums – never used, dunno
note that these are plugins and you need a DAW to use them. i understand you already have logic so that should be fine, then
edit: as for how "hard" drum programming is: it's not actually hard at all to make basic drum beats but as with everything, it takes practice to make stuff that sounds natural/interesting. having a half-decent understanding of how to play drums helps tons.
