Preamp questions.

So I have a Mackie Onyx 400f.
http://www.mackie.com/products/400f/update.html
It comes with 4 Mackie Onyx mic pre's. And 4 more inputs to allow me to add more outboard pre's.
I plan on doing track by track recording and I want to be able to record a full drumkit at the same time.
I need to add atleast 2 more pre's to my setup. Now I have been talking with a friend of mine who runs his own studio and he has some ideas but I kind of want to go a different direction, and I was just looking for another angle.
He has been suggesting I get a Yamaha mg mixer because they have decent mic pre's and for what I'm doing currently it shouldnt be a big deal anyways. The only problem with that is that I would then only be able to put whatever I run throuh the mixer onto one channel in my DAW because they don't have seperate outs for each channel. Just one main out.
I have been looking at getting either an ART Pro MPA II ( http://www.sweetwater.com/store/detail/ProMPA2/ ) or a PreSonus Blue Tube Dual Path ( http://www.sweetwater.com/store/detail/BlueTubeDP/ ) and just replacing the tubes with some higher quality ones.
Any other thoughts on what might be a good option for me? Or if I forgot to include any info to help you guys help me.

Either one of those would work for what you are doing given your price constraints right now. Although the higher end stuff usually sounds better, it is best to remember the most important piece of equipment you have are your own two ears and your creative imagination. Don't get hung up on stuff. As you mature as an artist you'll get what you need eventually. I started out with a Tascam 4 track porta-studio and an SM-57.:)

I actually just got a new job and im not so worried about price lol. But since im a novice at this i think it would be best if i was to start of cheap so i dont go in to far over my head. I think im gonna end up with the ART preamp. Thanks BluesMan

My first upgrade was to a ART TPSII micpre. Served me well. Don't use it too much any more since my last upgrade but I don't think you can go wrong with the ART stuff. I have an ART VLA Comp/Limiter that I'm pretty fond of also.:)

If you are only using two mics, the art will work. i have one, its ok. doesnt sound great, but it works, and has some nice features. stereo mixer with good pres will probably work/ sound better.