Hi Dan, longbow here. Your going to have a real problem finding a prod. bow with that draw length. They are just not made like that. They are made AMO standards where everything is judged by a 28" draw, hence the tiller for the bow is set that way. I don't think it would be problem finding a bow that you could draw to 31" at that draw weight but the thing would "stack", ie) increase in pounds pull inordinately to where it would feel extremely hard to draw even thought the weight wasn't that great. Although only drawing that much weight may not feel to bad maybe.
Think of it like this. If the bow draws say 3# and inch for the last 3" of draw that would be considered for all intents and purposes a smooth drawing bow. Now lets say you get to 29" and the bow increases another pound of draw to 4# in draw weight, then you get to 30" and the bow increases another for 5# in draw weight and then ad another inch to 31" and the bow increases another pound for 6# of draw. Well that just isn't going to feel good at all or be comfortable. I don't know if you have been measured for draw length but on a trad. bow I would say the avg. person would loose 2" or so of draw length over a compound bow being drawn. Shooting a trad bow is nothing like shooting a compound either. A trad bow is a more dynamic way of shooting and hunting. You don't hold the string nary for a second while aiming. You hold the bow with a bent arm, hit your anchor point and you should be on target and the arrow is away. I could go on and on on this subject for sure as I have shot a rec. or longbow since 1970 and have owned a few dozen probably during the course of that time. Some shooters and some not shooters. Kind of like knives it gets addicting to say the least.
I would be looking for a longer recurve or longbow say around 64"-66" and 38#@28". Speculating that the bow would draw 3-4# an inch beyong 28". You would have to measure the force draw curve for that particular to see if it fit your needs or was smooth drawing. I am speculating that a commercially made bow would gain in weight only 3# an inch passed 28" of draw, but probably that wouldn't be the case. So to compensate for that feeling of smoothness you would have too look for a longer limbed bow.
There are alot of factors that play into all of this. The shorter the bow the more percieved stack you will have cause the weight seems to build up faster due to the shorter limb dynamics. That and your fingers will be getting pinched by a shorter string so the perception of stacking in a shorter bow will greater too.
Try looking at the ads on the Stickbow site. You will have to register there but ask around and trust me you will find someone who is willing to trade for a knife or two. Tradgang.com is another good site. Have to register there too. Tons of info and everyone will be willing to share knowledge. Hope all this helps, keepem sharp