I didn't read all the comments, so if I repeat something that has already been said, sorry.
I patch out of soundboards all the time, and use an Edirol R-09HR in many situations (the other 2 decks I also patch out of boards with are the Sony M-10 and SD 744T). Depending on the soundboard, you'll with be coming out of XLR's, RCA's or 1/4". If it's a bar or similar size, the RCA's or maybe 1/4" will most likely be what you need, and of course terminating in a 1/8" to go into the R-09HR's line in. I have always had excellent results with the Edirol in these circumstances, so that would be my recommendation. When setting your levels, don't push them, stay between -12 and -6db, and raise as necessary in post. Keep in mind, however, in smaller venues, not every instrument will be routed through the board. More often than not, guitars, bass and drums will not be, or very minimally. When I patch out of boards in small venues, I use my 744T because I run mics with it as well (its a 4-track recorder). I only use the smaller 2-track recorders for festivals and larger venues that run everything through the board, and solo acoustic performances that is a guitar and vocals that both run through the board.
Hope this helps...tape on!