Haha I know I got lazy. Sorry.
Currently shoot w a Pentax k100d. It's been a great starting camera, but it's too noisy at a moderate ISO, 6 MP, can't shoot RAW, etc.... I'm ready to upgrade. And the MP does have something to due with it, considering people's iphones have better resolution. Most of my clients order enlarged prints so I feel like I need to offer a good product.
It'd be nice to go with the pentax k-5. Both cameras have good reviews on amazon, I've just been told numerous times to switch to one of the big names now, while I continue to grow and accumulate equipment.
I apologize, it certainly does sound like you're in need of an upgrade.
It would make sense to stick with the brand that you have already, allowing you to use lenses that you have already and making for a less awkward backup situation.
I know very little about the current Pentax line-up, so I can't offer any advice on the K-5 or any other models.
The 7D is certainly a decent camera. It's got some of the best focusing and metering systems that you'll find in a Canon camera. It's also a very fast shooter.
When you say that you'll be doing 15-30 'sessions'....is that portraits? If all you are going to do is a lot of portraits and one wedding (for now anyway), the 7D may not be the best choice, especially if you're on a tight budget....because you would be paying for fast shooting and speedy AF that you might not really take advantage of. A 60D or even a Rebel T3i would give you the upgrades that you need (more MP, better ISO performance etc.) but at a much lower price.
But to that end, whatever Pentax model you choose, would probably be a good upgrade as well.
I think that many people will still say that switching to Canon or Nikon is a good idea, but that is a tough pill to swallow, especially when on a tight budget.
How about this?....Could you get a better Pentax body, but a used one? That would probably be enough to get you through the next year. You may not have to buy any additional lenses and you'll have a matching backup.
Then sometime later, you can consider selling your whole Pentax system, and jumping ship to Canon or Nikon (if you want to).