thanks for the replies.

I've considered using one brake in the past to save weight. Having not the best bikes and beating them up a lot (I deliver on a bicycle), I've had to deal with only one brake on several ocasions, and I found that with only a front brake, I was much more likely to tumble over the handlebars when I applied the brakes hard (so if I had to have one, this would make me opt for a back brake). I know I have less control having just one brake, and I feel a lot more confident with two, but once again I've unfortunately gotten used to riding with just one, and I think I could manage safely, albeit not near as safely as possible, having just one brake.

What I am planning on doing now is keeping both brakes functional (safety first), and just dealing with a cramped right hand (my lefts hands okay cause I don't have a front derailleur/shifter). Unless I can find a shifter that, when butted against the brake lever, doesn't push my fingers towards the end of the handlebar (I like to have a nice wide grip on my bars).

On a related note... do most 8 speed shimano shifters go with 8-speed shimano cassetes? If I need to just google this for myself, please let me know guys. Thanks a lot.