http://myreadingmanga.info/pink-power-tiger-bunny-dj-box-eng/
There is this one, there are more but at least this will get you started? To be honest I'm not fond of them because in most Bunny is very feminine.
There is one that I liked I have to look around but if I find it I'll send you the link.
Ah, the rare "Kotetsu x Barnaby" dj! I prefer those too, but I hate it when EITHER of them is feminized. They're both grown-ass, independent mature MEN. (Okay, the word "mature" can't always be applied to Kotetsu, but that's just him having fun).
Try this one for now: http://myreadingmanga.info/tiger-bunny-dj-atarashii-hibi_katou-setsuko/
Barnaby's still a bit feminine here, but Kotetsu also has some fleeting shy moments so it's easy to forgive.
Yes, there's better ones out there and I can't remember their titles at the moment. I keep meaning to list them (for myself), but I haven't gotten around to it yet. I look forward to seeing what tisidafly finds.
There's really good one where both the characters were nailed perfectly, albeit in a very comedic way. I won't give away who-does-what because it would spoil the fun.
Unfortunately, it's in two parts and Mangago only has the first part. So back to My Reading for this little gem: http://myreadingmanga.info/tiger-bunny-dj-usagi-tora-eng/
Found one of them:
http://myreadingmanga.info/tiger-bunny-dj-invisible-man/
The artwork makes them look younger. And page 11...geezus, Kotetsu...WHOOT! While I'm trying to find one where he tops, I certainly don't mind him as a bottom because it's done so damn beautifully.