If you can use dragon magazine (or Dragon Compendium v.1) or Eberron, they all should have a generic monk feat to let you multiclass between monk and one other class of your choice. Don't bother if you're only going a few levels in one, though.
If you're willing to be double-plus good, Intuitive Attack for gods-know-why is an exalted feat in book of exalted deeds. Lets you use wis for attack rolls instead of str w/ simple weapons such as...unarmed strike. I would not go for Vow of Poverty, though, unless you know the DM to be lax on handing out treasure. It looks way better on paper than it is in play. DEFINITELY don't take it if Magic Item Compendium is allowed.
From tome of battle, there's superior unarmed strike, which counts you as +4 monk levels for unarmed damage, possibly useful. I think this number can exceed your HD, so useful even to a pure monk. The book also has Snap Kick, which basically lets you make an extra attack at full BAB (and half str on the damage) after any other attack action s completed, but all attacks suffer an extra -2, kinda like flurry. The awesome part here is, unlike almost all other bonus attack abilities, this can be launched off ANY attack, not just a full attack. You could do it after a charge, for example.
For stat distribution, don't ignore str. A lot of people think monks don't need it, but it helps with many things you want to do. I'd say if you can do point buy, go for as many 14's as you can. You want some str, dex, con, and wis. If you're doing rolling, hope to get a bunch of medium bonusesand almost nothing low, rather than one or two very high numbers and the rest straddling average. As a cleric, too, you might want to invest a 16 is wisdom, but it can get expensive, especially with point buy.