if you have dollar tree around your house.
thay have usb extentions for $1 dollar each.
these work just fine , even on a printer. 5 cords is as far as I have hooked together but my printer still worked fine that far a way.
I do not know how many you can hook up before signal gets week.
I remember Tech TV (Scren Savers) did something like 50 feet

Lowes has a metal hole saw for like $10.00 maybe $15.00
get some small (auto vacume hose) slice it down the middle
put this over your hole (to protect your usb wire or any small kids who will eventually sneek back there.)
that is how I would do it. also later on you can find a metal plug to cover up hole if you ever wanted to
I found a thread in software forum. There is several programs that will find all the USA roms. (I also told it to find English) and only the files that had "!" mark meens known to be a perfect dumped rom)
I have got my roms down to a few 100 each.
but now I play a game and If we think it was a keeper . I started a list on the PC of the games we like.
seems like maybe 10 to 15 games on each system
the emu,s I use are
Nestopia = NES
ZSNES = Super Nes
Project 64 = Nu64
Fusion = Master and Genesis
magic engine =TG16