Hmmm...the problem w/ your request is the word "reliable"...
I do about 80% of my own booking, and what I do is contact the venues several months to a year in advance of when I wish to tour, and just do all the "hustlin'-work" (send out promo stuff, and the ever-delightful "follow-ups") myself (well, actually, my wife has taken over some of that for me).
The other 20% is broken down to about 5% booking agents contacting me, and 15% where the venues I've played over the last 25 years contact me w/o going thru an agent. (Saves them $$$/makes me more $$$)
The most important piece of touring equiptment, besides a nice guitar, is a good lap-top computer to keep all the relevent details together in an organized form. (What a concept...an organized musician!)
There's a really handy book out there called "How to Be Your Own Booking Agent and Save Thousands Of Dollars", by Jeri Goldstein (New Music Times), about $25...a "must read for any "alternative" artist (anyone other than Garth Brookes/Mettalicca wannabes) & an excellent investment.
Hope this little bit of info is of some help to your buddy.