If you are to use crossbows, Rapid reload is essential and you may want to look at crossbow sniper from PHB2.
Obviously, you're going to want to take the TWF chain.
Once you get a high enough caster level, you'll also want to take Craft Arms and Armor, and see if you can put an "auto-loading" enhancement on your crossbows.
Quick Draw will help out until then. That way you can keep a couple of spare loaded heavy crossbows for the first round, and won't have to spend time reloading. Check with your DM to see if he will allow this tactic.
For paired crossbows all you need is 2 weapon fighting feat tree.
See, the 2 weapon feats allow you more than one attack at a time, however reloading two hand crossbows effectively sucks. Using the ranged combat feats helps with more than just the crossbows, it helps when you decide to start throwing other weapons at the enemys, say the random thrown fullblade or dwarven urgosh. In the end I just went with firearms and saved myself the massive reload time by making it a revolver.
Two-Weapon-Fighting is actually melee weapons only; there are no feats I know of that allow you to reduce the penalties for fighting with two ranged weapons...
|
Only somewhat on topic, but if you decide to build a flintlock-pistol or hand-crossbow slinger, you might want to hunt down a copy of Ral Partha's old Dwarf with No Name miniature. Shown here, it has pistols, but it would be quite easy to modify them to hand crossbows.
Don't ask me what the holsters might look like.