Get the 633. It has everything you need for small shoots. I have the 664 and typically only use 2-3 channels. So for me the 633 would be a cheaper and perhaps more shoulder friendly unit.
Just want to chime in that I own a 302/702T combo and I think you should go that route for several reasons. One is that the 302 sounds like it will provide plenty of channels for what you will be doing. Basically you can do 2 lavs and a boom, which is essential for even the smallest productions. Second is: the 702T has the timecode generator, and shooting with timecode on a small production can save a lot of time in post. Third: the kit is compact and will provide you with everything you need. I run my 702T recording to the compact flash card and also to a FireWire bus powered ssd drive for backup. I often just give the drive to someone because it's easier than taking my bag apart to get to the compact flash card. Fourth is: with a 302/702t you can record sound with your recorder AND send signal to a camera, which is good when the camera doesn't have great sound. I've found the 702 delivers superior quality when compared to most low/mid level cameras you'll find on smaller shoots
I own the 633, it is terrific. I like the time code built in and no brainer for mixing and recording to two mediums simultaneously. I have used it with Sony F3, DSLR, wireless and boom. It is well worth the price.
Take a good look at the Zaxcom MAXX while you are still in this stage. You can get the basic unit for pretty cheap and expand it as your needs change. Add in their digital wireless and you have a powerful setup.
I also have the Stingray bag from K-Tek which is great with the 633, much better than any other choice I could find. I am not a sound professional but the quality and convenience of the 633/Stingray make me happy. I looked at the MAXX and it just seemed more complicated while at the same time more versatile but for anything I can imagine doing the 633 is a better fit. I do like the idea of wireless with the backup on the Zaxcom transmitter device. Either way take a look at the very clever Stingray it works for both MAXX or SD633.
At the price range you are considering, the AETA 4MinX is also well worth looking at.
High quality mic. pre-amps - good for music recording to CD release.
10 inputs - level adjustments on *all* inputs including line in and digital in (including AES42 digita mics)
Last month's update added the ability to add delay on any or all of the inputs - meaning that you could use a Schoeps SuperCMIT, which can have a long processing delay) and delay the radio mics and analogue mics to be in sync. with the SuperCMIT.