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Im making a rehearsal room, witha possibility to record a demo, for example.

So I was thinking about gear I made a little list, and would that be good ?
- Guitar amp, I need two, so - some Fender Bassman/Silverface from ebay, but I dont know how reaible they would be.
So from the new amps I chose these : Fender Super Sonicthis , Marshall MA50H this , and for bass (I dont know anything bout' bass) Marshall MB150 (some kind of tube/solid hybrid)this .
- Mixing console : Allen & Heath ZED-14 (with an USB out) this

Some SM58s for vocals, and a set of Shure drum mic set , and an MXL condenser for vocal recordings.

About making it loud -
I was thinking about putting the mixer signal to the power amp this and then to these .

And I was thinking of buying an little electronic piano, or getting a real piano and somehow getting it to the mixer. (shure 57s or condenser, make a piezo pickup?)

Maybe some suggestions, I have been saving money for this for some time now, and I want to make it a decent rehearsal/recording room.

Looks like you're on the right track. I take it you have a computer and interface to use with the USB output from your mixer. With that set up it's likely you'll be recording the stereo output from your mixer (2-channels)--which could be ok depending on how things are positioned and mic'd. I'm not that familiar with that mixer; but if it has individual channel inserts or direct outputs you could route those to an interface with more inputs to the computer and do more multi-tracking. In any case, looks like you're covered for the most part. I'm generally not a big fan of "drum mic packages"--I think you'd be better off assembling a mic locker with individual selections. You can get some mics used to cut down on the cost. It will provide you some more variety to use for overdub duties as well. Also, nice of you to go buy gutiar and bass amps; but won't your prospective bandmates have their own? Seems a bit much for you to ponying up for the recording and live music gear.

Are you looking to record live? If so you'll need a lot of kit.
If not then you'll get miles out of a pair of 57s and a few good condensors.

Also look into asansamp type DI for bass. Its a lot easier to deal with and a lot of people prefer at last a mixed singal.
Bassmans are great amps and really reliable. I own one myself. Like any tube amp, especially of any vintage, you need to make sure it ha had its proper maintenance done. Bassmans certainly have their own sound and they aren't for everyone. They aren't exactly a clean amp once you get to rehearsal/gig volumes. I think a twin or something would suit a studio better if you want a solid clean amp to use.
As far as drum mics go, check out the Glen Johns method. One overhad, one over the shoulder, one in front of the kit and a snare close mic'd. Surprising results with a bit of leveing and eq. Also doesn't break the bank.
Id also recommend the beta 57 over a 57. Its a little more diverse. Good for vocals (I find it akward singing into a 57) and on snare, since its a super cardiod, you can get some nice high hat bleed

AKG D5 is about half the price of the Shure, great reviews online. I have one.