1. MSI makes a really decent motherboards, contrary to what you might read on the internet. I have one, so does my brother, and we both had a few before, never had any problems with any of them. Though, if you think you might want to expand sometime in the future, maybe you should look at some other model, with more PCI and memory slots. Two memory slots might seem enough, though, you can easily pack 8GB in it, no problem. But the PCI slots might be a bit problematic. Add a dual-slot PCI-Express graphic card and a sound card, and your graphic will surely build up excessive heat because of the lack of air flow (unless it's has a water cooling). Tight space and all that. Overall, it's OK.
Mine has 3 PCI slots + 2 PCI-E, and with dual-slot graphic, between that and soundcard, there's about 1 slot room, though if I plug anything in it, temperature on the graphic will go through the roof. On my previous motherboard, it had 2 PCI slots and 1 PCI-E, and it literally popped the capacitor on my old single-slot 8600GT card due to the excess heat. Surprisingly, it worked for about 5-6 months with 3 busted capacitors. It was a miracle it didn't fry my motherboard or anything else
So, that's something to think about.
Though, if you have enough money and aiming for the quality, personally, I'd go with Asus anytime. Their motherboards cost a bit more (in some cases, a lot more), but the quality of those is excellent... at least it used to be.
2. I'd go with X4 processor. If you're new to music production, you will easily stress out your CPU, till you learn to organize and optimize your songs better, so a little extra power doesn't hurt. I have an X2 @ 2.5GHz, and it can be stressful sometimes. Though 260 is @ 3.2GHz, so you might be ok... depends on your needs.
3. 4GB of RAM is fine... unless you're going to work with a lot of audio - samplers/romplers, loops and stuff like that. If you're going to work mainly with synths and occasional sample here and there, you won't ever need more than that.
Overall, there's always a trade-off, unless you have enough cash to fork out for a "little kids eating" machine.
But basically, if you're doing a lot of synths and effects, go with the better CPU. And if you're doing a lot of audio, go with more RAM. That is, if you already have to make compromise. If you don't, then go with more of everything