I'm presuming by the fact you already have all the profs, that you have quite a few characters already and so you don't care about minmaxing to the point where every single point matters (unless you plan to make the monk your main for raiding). I picked engineering/mining (and later changed mining to enchanting) on my monk just because it was a Gnome and I didn't have Eng on any other char but I found out that Engineering is an incredibly fun profession. The invisibility belt enchant, the gloves tinker which has the same cooldown as tigerseye brew, the goblin glider and many more are THE THINGS that make the profession more exciting than all the other boring profs. The only thing (of which you may already know as this is true for all healing classes) is that if you'll play a healer, you'll have a problem early on during gearing up. There's only 4 healing cogwheels and with the eng. helmet and the ghost iron dragonling, you'll have 5 cogwheel slots. Other specs are fine and as soon as you'll find a better trinket or helmet, you'll be fine as a healer too.
Sounds like you have an excellent plan. If I were to start a new toon and I was going purely for raid viability I'd go Engi/BS too. Engi has the best controlled burst increase and BS has the same static increase as others BUT the possibility of upgrade once we get Epic gems towards the end of the expansion.
For myself though, I'd go Herb/Inscription, then drop herb and take up Alchemy. Easiest way to make some gold on the side + killer with a new expansion. And it's not bad for raiding either. Good shoulder enchant + longer, better flasks is pretty win.