Most hosts try and confuse you with lots of features that are basically meaningless on a minecraft server. The ONLY thing you really need to pay attention to is RAM. You'll notice that ALL of the hosts are extremely grudging with that one category because it's the only one that counts.
If you're going to actually have 10 people on your server, running FTB... you'll probably need 1GB at a bare minimum. I have allocated my server 4GB and it has at most 3 people on it... it consumes about 2GB on average.
This is why I run my own linux box on old hardware. Turns out RAM is cheap if you buy it yourself.
I do not know where that you have learned this but you are completely wrong !
Dont go out and giving false info please.
The correct info is that your host, providing all those details ARE very important !
There is more than just RAM to a server, and very much to a Minecraft server !
Let me sum it up.
Hard drive speed:
Minecraft is a write/rewrite application. It needs a lot of Writing speeds and a lot of IOP's from your storage media to keep up.
A normal HDD will have a maximum of 175 IOP's, minecraft will KILL this instantly. A SSD will have between 20.000IOP's up to 200.000IOP's depending what chipset you take.
This is extremely important for map write and rewrite's. Also all flatfile's take use of this.
CPU:
The CPU is important again since the java aplication will usea lot a CPU power to manage all its data flow. Anything will get computed threw the CPU, the ram is just a fast storage to get and store info from.
A bigger LN2 cahs in a CPU will improve data flow and prosessing speed. Also the newer chipset range you take will make sure the CPU is more powerfull. To explain the last part.
A 1366 Socket CPU with 2.6Ghz will be SLOWER then a 2011 Socket CPU with 2.6Ghz (Both over single core) This is thanks to the argitecture changes in the CPU itself, the newer series can handlle bigger data packets instead of having to split them up basicly.
Ram:
Ram is also not to be forgotten but the 2 objects above are equally to more important. Your ram is basicly just a fast read/write storage. It will NOT prosses anything it will just hold it there for the CPU or Hard drives to use. A larger Ram size is usefull upto a point. But if your CPU cannot keep up it is useless.
Again ram hase a couple of features you need to take in account. Its Mts and the timings. The timings are "Latency" and the lower the better. A good standard to take for DDR3 is between LC8 and LC9.
The Mts is the data transfer rate/s. This will usually on DDR3 be arround 1333 and 1600. There are higher ram dims but those will again drop your timings.
Network:
This needs to be able to hold a lot of data. Especially with Modder servers. Every switching wire is a block update that needs to be send out, also every cable that has power needs to be calculated every tick. A tick is a part of a second in minecraft. There are 20 ticks in 1 second. So you are sending out 20ticks a second of data for anything that is working. This is , machines, cables, redstone, and so on.
These packets can grow bigger depending on the size of what you build. I am talking about a bandwith of 350Gigs to 500Gigs / month for a 24/7 Server with 25 players