Good hotel that's quite near the Q Bar is the Manhattan on Soi 15. Mid-range price, good value and guest friendly too.
By the way, central Sukhumvit really isn't that long. For instance (and assuming you're sober
), you can walk from Soi 4 to Soi 33 in about 20 minutes. And that will take you past all the major hotspots such as Nana, Soi Cowboy and the artist bars. The only hotspot it doesn't take in is Patpong, which most people could live without anyway.