Debian :: Sharing A Lot Of Files

I have been a happy linux user for some years now, even at my work i slowly changed windows to Debian in my computer. I need to share files to others computers (windows 7 and linux).

I have debian stable, xfce and samba whit a public folder. This setup has worked great whit a reasonable number of files ( under 1000) but now i have almost 10.000 and is getting too slow to scan the files when i enter the folder (in the client side, both windows and linux machines) so i think the problem is in the server side (my debian+samba). The files are not heavy (100kb to 2mb) the problem seems to be how much files there are.

Sharing IS WORKING but i would need it to be FASTER, So i need to share the files whit 4 pc running different OS

Ideas:

1) i could tweak samba to make a better job. I have tryed some configurations i found in forums but problems remains. I read that i could make a cron job to LS to the network folder every minute, so it will be ready when i need it, but this solution seems to me very inefficient, using a lot of cpu in the others machines

2) i could change the sharing software. Maybe samba is limited and there are others better way to share a lot of files. I could even install a debian-server version that is more prepared to do this job (if they are)

3) I could buy a router whit a usb 3.0 and attach a external hard drive. I already own an external hard drive that is usb 3.0. This should be more easy and even better (router never turn off so files would be always avaible) but i dont know if this will be faster or slower until i try it, which means to spend money. I could buy the router linksis Cysco EA6200: [URL]