Or, you could try starting off with a minimalistic mod pack and add on rather than start with something like Ultimate and pare down. Here's where I plug my own
Mod Pack, because it really
is a good example of a minimalistic mod pack, but it is by no means the only one.
The draw to my mod pack is it all runs on a single power network (MJ). No EU, No Bluetricity, no Factorization lead wiring. Also, because it doesn't have a bazillionty mods, it's fairly easy to get started with. It can introduce you to some of the more common mods (Thermal Expansion, Tinker's Constructs, Modular Powersuits, Applied Energistics), but doesn't bury you in fifty zillion new biomes each with it's own pointless shiny things.
The downside is, of course, no IC2, no Redpower2 (because it's for 1.5.2), and many of the things you'll find in Ultimate aren't there. While you have more options than Vanilla, you may find there are not as many ways of accomplishing the same task as Ultimate.
There should be an update going 'live' sometime today with a couple of fixes. Most importantly, I was using an outdated Iron Chests version which didn't connect well to Pipes and didn't like Forestry bags, but also the update to Applied Energistics 11.a (11.b will have to go in next week, because it didn't get updated until yesterday and Thursday is the cutoff for mod pack update submissions). If the Version is 1.3.1, then you're good. Otherwise, wait a couple of hours.