Suggest a basic upgrade for LTC mining on Mac Pro

[EmberMike]

I'm new to mining, both BTC and LTC, and I want to focus on LTC on my Mac Pro. My setup is a 2010 Mac Pro Westmere 3.2Ghz Quad-Core Intel Zeon, 8GB RAM, ATI Radeon HD 5770.

I'm currently seeing average HR of 60-70kH/s while still keeping the computer usable for other things. Cranking it up I can get 120kH/s but the system slows to a crawl and I'm worried about burning something out.

So keeping in mind that I'm also not exactly technically advanced when it comes to hardware, and that my comfort level with tinkering around in the box would max out with doing things like swapping a GPU or adding RAM, what would you suggest I do to upgrade my system to get better hash rates?

Would a simple GPU upgrade help? Anyone know what my options are with this Mac?

[EmberMike]

Just bumping this because it got moved and buried. Hope that's ok...