You wanted opinions, so here it is.....
Based specifically on what you want to do and the games you mentioned it's probably one of the dumbest ideas I've ever heard. Why? Well let me go down the list.
#1, Cost:
For each system you will have to hack a couple of pads. Some of the older pads are cheap, but most are still 20 bucks a pop. Plus your going to have to get a high-end av switcher to handle all of those systems and switch automatically. That's going to add up. It would be more econimical to put a low-end pc in there.
#2. Game selection: Literally every game you mentioned is emulated by mame. Up until around 1998, arcade versions of games are almost always superior. So you are going to all of this trouble to play crappy, watered-down ports of the original.
#3. Complications: You'll have to cross wire all of those pads to a common control panel. It's going to be an ungodly mess. And the more complicated something gets, the more things can go wrong.
#4. Common sense: So you like reaching your hand into the back of a cabinet and trying to stuff a cartridge in a slot in the dark, trying not to knock over the other 12 cosoles stuffed in your cabinet? How about standing up, 1 foot from the screen, playing console games, which the majority of are designed for long term play (e.g. several hours, not several minutes)? Consoles are consoles for a reason.
Even running emulated consoles on a mame cab isn't the best idea in the world because of the things I just said in #4. I do run a select few console games on my cab but they are special cases. While I'm rambling on here I might as well put down the ONLY reasons to run console games on a mame cabinet.
#1 The game in question is a "sequel" to an arcade classic that was only released on the console. (Like final fight 2/3 and slaughterhouse 2/3)
#2 The game in question has an arcade port, but it isn't emulated yet (the only example of this, in this day and age is the newly released chankast emu, which runs naomi/cps3 ports)
#3 The game in question is one of those magical games that fit well on a cab and include all of the follow traits:
It uses all digital controls.
It has large, easy to read menus/graphics.
The gameplay type is short and uncompilcated.
It sounds like there are a lot of games that would fall into that category, but not really. To give an example, here are some popular console games that won't work and the reasons why.
Super Mario World:
The game is extremely long.
Game loading/saving is done via a farily complex menu system, which slows down the pace and detracts for the arcade "feel" you are looking for.
Street Fighter 2:
emulated by just about every arcade emu out there
Mortal Kombat:
Ditto
Sonic:
Actually not too bad, but again, the game length is waaay to long, even compared to some of the more complex arcade platformers.
I'm not saying all of this to discourage creative ideas, but to keep you form making mistakes that have already been made by others countless times. It's been tried again and again, but in the end, anyone who made a "console cab" will tell you that eventually it was either abandoned, or upgraded to a proper mame cab.
Consoles have their place, and usually that place is under your tv in your living room next to the couch.
