If I'm not mistaken, TradTech was the first to bring a short hunting riser with the ILF connection to market with the Titan. Since then, they have introduced a number of other risers both shorter and longer. There have been a number of others since then like SKY, Morrison, Dryad, 3 Rivers and Hoyt, all good choices. Limbs are available from at least a dozen different makers, both custom and production.
To add to what Ray Lyon said, in addition to limb angle, riser length also dictates what weight a given set of limbs may actually be. For example, a set of limbs that are 50 lbs on a 17" riser might be 52 lbs on a 15" riser, 48 lbs on a 19" riser, 46 lbs on a 21" riser, 44lbs on a 23" riser, etc.
In addition to that, each riser-limb combination will also have about 10% of weight adjustment. For example a combo that is 50lbs at the middle preload setting, might be 47 or 48 lbs on the lightest setting and 52 or 53 lbs on the heaviest setting.
Like Koger said, Lancaster is a good resource because they have a number of risers in stock from different makers and materials and a number of different limbs in every price range that they can mix and match to your exact specs.
It sounds complicated but it really isn't. Most people just find a combo they like, set it for how they shoot, and forget it.