Well, make your own. I have a home made one that uses 16 AA eneloop batteries. I have it wired for just 9v output but I could easily add an 18 v output. It lasts forever, can run on 8 or 16 batteries. I even added a cheap led voltmeter on it to see where my batteries are. Eneloop batteries are great because they will charge like 1500 times, will retain 85% of their original charge even after a year and will run at a decent voltage until they are almost flat. I have been using those for my macro photography hobby for years and they have never failed me.
Right now, the pack powers: TC Polytune, T1M buffer, EHX Mole, MSLP Looper, WH Pork Loin, Micro Thumpinator, Grey Stache, Rat King. I will add a OSD to that when I get it. It works great, lasts forever, no noise. I did have to add a diago isolator on the MSLP looper however, but other than that, super quiet.
I can post photos of the pack if you want.
Fuzzrocious #136, Phil Jones Bass Club #51, Short Scale Bass Club member #393